RWTH Aachen University Research Articles

Functionalization of All-Oxide Ceramic Matrix Composites Elements Using Three-Dimensional Braiding and Pressure Slip Casting for Composite Processing: Approaches to Reduce the Filter Effect of Dense Reinforcement Textiles

Abstract A key element for the transition to sustainable energy lies in the transformation of the power plant fleet, which is dominated by fossil fuels, toward sustainable energy production from renewable energy sources. An increase in efficiency and reduction of exhaust gas emissions, especially the minimization of CO2 emissions, is possible through the use of new turbine materials, which can withstand higher temperature levels. Oxide ceramics are well known for their high stability in aggressive environments, low density, high melting point, high stiffness, and great creep resistance, but their brittleness has strongly limited their number of applications. Therefore, the implementation of fiber reinforcement using the three-dimensional (3D) braiding process shows great potential to increase the damage tolerance of ceramic matrix composites (CMC) and consequently the performance of thermal machines significantly. Currently, the impregnation of 3D braids for the reinforcement of ceramic composites poses a challenge due to the high packing density of the textiles. In order to enable a homogeneous impregnation of the fiber structures using highly viscous ceramic slurries, the CMC research group at RWTH Aachen University's Institute of Textile Technology (ITA) is investigating the combination of 3D braiding and pressure slip casting for an economical production of all-oxide CMCs. To increase the impregnation quality of dense textiles, this paper describes approaches to reduce the filter effect of braids. The results of an initial investigation into the functionalization of two-dimensional braided reinforcement structures by using support structures and flow aids are described. The effectiveness of the impregnation ability is assessed by evaluating the residual porosity of generated green compacts via μCT analysis.

Safety and feasibility of sutureless pars-plana vitrectomy in sub-Tenon anesthesia (SAFE-VISA): a prospective study

BackgroundTo determine the safety and feasibility of sutureless pars-plana vitrectomy (ppV) in sub-Tenon anesthesia.MethodsIn this prospective study. Pain and anxiety at various times after ppV using a visual analogue scale (VAS) and Wong-Baker-FACES scale as well as visual sensations during surgery were investigated. The surgeon evaluated motility, chemosis, overall feasibility.ResultsppV was performed on 67 eyes (33 sub-Tenon anesthesia, 34 general anesthesia). Pain during surgery in sub-Tenon anesthesia was 1.8 ± 2.2 (0.0–8.0), anxiety was 2.3 ± 2.2 (0.0–8.5). There was a moderate correlation between pain and anxiety (R2 = 0.58). Comparing sub-Tenon and general anesthesia no difference in pain perception was found the day after surgery. 27.3% of patients saw details, 21.2% saw colors, 90.1% saw light/motion perception, 3.0% had no light perception. Median chemosis after surgery was 1.0 (IQR = 1.0). Median motility of the eye during surgery was 1.0 (IQR = 1.0), median grade was 1.0 (IQR = 1.0). 24.2% of patients showed subconjunctival hemorrhage during or after surgery.ConclusionsSutureless pars-plana vitrectomy in sub-Tenon anesthesia was performed safely, with pain and anxiety levels tolerable for the patients and without the necessity for presence of an anesthesiologist. With 88.9% of patients willing to undergo vitreoretinal surgery in sub-Tenon anesthesia again, we recommend it as a standard option.Trial registration This study was approved by the Institutional Ethical Review Board of the RWTH Aachen University (EK 111/19). This study is listed on clinicaltrials.gov (ClinicalTrials.gov identifier: NCT04257188, February 5th 2020).

Urban Project, a Matter of Morphology

This research faces the theme of the actuality of the Urban Morphology discipline. Starting with the reconstruction of the history of urban studies in the schools of architecture in Italy in the last century, a personal approach to the theme is proposed as a result of an intense activity of academic cooperation of the authors (from the University of Naples Federico II) with the research group of Uwe Schröder (RWTH Aachen University in Germany). The main innovation, if referred to the Italian tradition, is that the city is now observed not only from the point of view of the ‘form’ but also considering the ‘space’: thus, the different qualities of the spaces that build every city and its wealth. The ‘results’ of this research are in the projects that the authors develop on different academic occasions; in fact, in Architecture, theory and practice are strictly connected. This is the reason why two projects are described at the end of the study in order to demonstrate that only a disciplinary knowledge of the city can produce its responsible modification, while more general ‘Conclusions’ define the innovation that the study proposes to the debate on Urban Morphology.

A real-time auralization framework for scientific experiments

The software Virtual Acoustics (VA) is an open-source auralization framework developed at the Institute for Hearing Technology and Acoustics, RWTH Aachen University, Germany. Using physics-based models for source emission and sound propagation, it allows plausible rendering of virtual scenes based on purely synthetic data. Its modular design provides a variety of rendering modules using different assumptions for the sound propagation. This allows the rendering of various indoor and outdoor scenarios with adjustable degree of complexity. Based on a similarly modular concept, VA allows a flexible way of reproducing the sound via headphones or loudspeaker arrays. For this purpose, the signals can be spatialized using binaural synthesis, higher-order ambisonics or VBAP. The respective scenarios, including source and receiver movement, can be controlled using the C + +, C#, Matlab, Python programming languages. Additionally, there are interfaces for the Unreal and Unity game engines allowing the combination with sophisticated visual cues, e.g., using HMDs. The software’s flexible structure and configuration possibilities enable the controlled application in listening experiments while providing an adequate level of plausibility. This work discusses the options as well as the limitations of the software and presents application examples in scientific experiments.

RDM in Chemistry: How to Educate and Train Future Researchers to Manage Their Data

For in-depth research data management in chemistry, a cultural change is inevitable. To foster this change, future researchers need to be educated accordingly. The presentation will provide an overview of the first teaching approaches in student courses in chemistry at RWTH Aachen University. On the long range, the integration into curricular teaching is key to the cultural change.

Applicability of multi-criteria decision analysis in the site selection procedure for high-level radioactive waste final disposal: robustness-oriented comparison of emplacement concepts

Abstract. The verbal and argumentative approach predominantly practiced in previous repository projects is only comprehensible to the general public to a limited extent (FKT, 2021; Blattman et al., 2023). One option to improve the transparency and the comprehensibility of decision-making processes is to supplement verbal and argumentative approaches with multiple-criteria decision analysis (MCDA) (Geldermann and Lerche, 2014; Frieling et al., 2020; Blattman et al., 2023). In nuclear waste management, MCDA has been used sporadically with respect to disposal strategies and site selection procedures (Achillas et al., 2013; Frieling et al., 2020). For the German site selection procedure, Frieling et al. (2020) identified the potential suitability as well as the development and testing needs of MCDA. Collaborators of the Chair of Repository Safety at RWTH Aachen University are investigating the applicability of MCDA for specific decision problems in the German site selection procedure. One decision problem is the emplacement of high-level radioactive waste (HLW) packages, which is being researched in the context of a doctoral thesis. For this decision problem, influencing factors and interdependencies between decision criteria, for example operational and long-term safety, and between other decision processes in the site selection procedure need to be considered. In the research project presented here, the emplacement of radioactive waste packages is categorized into three concepts: (1) drift emplacement and (2) horizontal and (3) vertical borehole emplacement. All concepts are tracked internationally. In principle, the Bundesgesellschaft für Endlagerung (BGE) evaluates the three concepts as feasible. However, for the performance of the representative preliminary safety investigation (rvSU), the drift emplacement concept is preferred, which is verbally and argumentatively weighed in BGE (2022). In this present research, the applicability of MCDA to the decision of the emplacement concept with respect to the German site selection process is explored in four main iterative steps based on Belton and Stewart (2003): (1) decision problem definition, (2) problem structuring, (3) decision model creation, and (4) verification. Currently the decision problem is being structured. Preliminarily, testing of the applicability of the sequential MCDA methods Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE) I and II is planned, although the method selection has not been finalized (Brans, 1982; Brans and de Smet, 2016). Furthermore, the combination of different MCDA methods will be elicited. The expected outcome of the research project is a basic decision model for robustness-based comparisons of disposal concepts of HLW. The decision model has the potential to provide decision support and to identify areas for further research regarding safety investigations as well as an increase in transparency, understanding, and acceptance in the site selection procedure. When MCDA methods are adequately applied by the decision maker, benefits are possible in terms of problem structuring, information processing, integration of qualitative and quantitative factors, deeper insights into relevant factors, and identification of compromises (Geldermann and Lerche, 2014; Frieling et al., 2020). Furthermore, the research results are particularly significant for international site selection procedures that are at the beginning of the selection procedure or at a comparable level in the German procedure.

Bearing capacity of headed studs under combined tension and shear loading in composite beams with large web openings

AbstractThe use of steel‐concrete composite structures with a high installation grade is becoming increasingly popular in building and industrial construction. To reduce construction height building services are routed through web openings in the girders. However, these openings represent local points of interference where, in the case of composite girders, parts of the acting shear forces are transferred from the web of the steel profile into the concrete slab. This results in additional, local stresses in the remaining steel girder and in the concrete chord, which must be considered in the design of the floor girders and shear connectors. Web openings in composite girders are not addressed in the current European design standard for steel‐concrete composite construction (EC 4). Only with the introduction of the second generation of Eurocodes in the coming years this case will be normatively regulated. During the preparation of the standard further questions about the load‐bearing behaviour arose, as the existing design approaches usually only consider a selection of possible failure scenarios or neglect essential verification steps. A joint research project between the University of Kaiserslautern‐Landau and RWTH Aachen University aims to develop a suitable design concept for composite girders with web openings. Model and beam tests accompanied by numerical simulations will provide further information on the complex local and global load‐bearing behaviour of the composite girders.This paper presents the results of experimental investigations and numerical simulations on the influence of large web openings on the global load‐bearing behaviour of the shear connectors in the composite joint. Based on 60 pull‐out tests and numerical simulations, the load‐bearing behavior of head bolt anchors under combined shear and tensile loading was researched and evaluated.

Transient Solid Oxide Cell Reactor Model Used in rSOC Mode-Switching Analysis and Power Split Control of an SOFC-Battery Hybrid

Defossilization of the global energy system requires a transition towards intermittent renewable energy sources and approaches that enable efficient conversion of primary energy sources into electrical energy. Due to their high efficiency in converting chemical into electrical energy and vice versa, solid oxide cell (SOC) systems provide solutions for both of these aspects. Within this contribution, two researched cases utilizing SOC's are presented, based on simulation studies and experiments.Characteristically, SOC reactors produce hydrogen from steam in solid oxide electrolysis (SOE) mode, or electricity from reformates in solid oxide fuel cell (SOFC) mode. An application of both modes as reversible solid oxide cell (rSOC) is to balance a renewable power supply with storage and power production, leading to high utilization of the same equipment. An application in SOFC mode is the maritime transportation powertrain. In both cases, transient operation is needed whenever mode transitions occur. In particular, switching between rSOC modes implies transitioning exothermal SOFC, endothermal, thermoneutral and exothermal SOE operation. Similarly, supplying the power demand of a maritime drivetrain in SOFC mode leads to various exothermic levels, as pertinent to part or full load operation. Operating strategies are needed to suppress potentially damaging thermal stresses during these transitions in the electrochemical SOC reactors. In order to identify such operating strategies, experiments have been carried out and a transient model has been developed for the analysis of rSOC mode-switching and SOFC drivetrain power supply, which are presented in this study. The 1D+1D SOC dynamic multi-reactor model includes the individual SOC reactors, piping and insulation, and is implemented in the in-house developed transient energy process system simulation framework TEMPEST [1,2]. The model couples the transient balances of mass and energy with electrochemistry, internal reforming kinetics, heat transfer, and flow distribution. As a result, temperature and voltage characteristics at cell, stack, and module levels are obtained to analyze for e.g. unwanted thermal stress. In the EU project SWITCH [3], experiments were performed at DLR with a Large Stack Module (LSM) from SolydEra (formerly SOLIDpower) to validate the model in transient 75 kW electrolysis mode, 25 kW fuel cell mode and mode-switching operation between electrolysis and polygeneration mode. The so called polygeneration mode refers to simultaneous generation of hydrogen and electricity at partial fuel utilization with natural gas, biogas or e-methane. Simulative studies of mode-switching procedures from SOE to SOFC-mode polygeneration show that drawing fuel cell current soon after reaching open circuit voltage and sufficiently in advance of the methane ramp completion leads to a reduced temperature decrease at the inlet of the cell without reaching oxygen to carbon ratios low enough to favor carbon deposition. In the EU project NAUTILUS [4], the mismatch between the transient response possibilities of SOFC systems and the power demand of a ship is addressed by connecting Li-ion batteries to the powertrain. Batteries respond to highly transient ship load demand changes, while the SOFC’s provide base part load to full load, according to a power split control strategy. A battery model developed and parametrized by the Chair for Electrochemical Energy Conversion and Storage Systems of RWTH Aachen University [5] was added to TEMPEST and validated using DLR experiments with a 40 kWh Li-ion battery. Simulation results of the SOFC-battery hybrid in Figure 1 show that a rule-based power split control strategy [6] ensures that the power demand of the ship is met at all times while the battery state of charge (SoC) remains within specified range, and the SOFC power is drawn at one of three fixed power levels for reduced thermal stress. An experimental campaign to test this and other control strategies with a 32 kW LSM from SolydEra and the 40 kWh battery is in progress at DLR. Acknowledgements Project SWITCH has received funding from the Fuel Cells and Hydrogen 2 Joint Undertaking (now Clean Hydrogen Partnership) under Grant Agreement No 875148. This Joint Undertaking receives support from the European Union’s Horizon 2020 Research and Innovation program, Hydrogen Europe and Hydrogen Europe Research. Project NAUTILUS has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 861647.

Transition from intensive care to palliative care : A retrospective analysis of 102 consultation requests

The transition of patients from the intensive care unit (ICU) to the palliative care (PC) ward often implies changes including establishing apalliative concept. Adaptation of therapeutic goals can be challenging for medical staff, patients and relatives; however, descriptions of these transition trajectories are rare. The aim of this retrospective study was to characterize the consultation requests of the ICU to the PC consultation team as well as the patients by a description of trajectories and interventions. Retrospective analysis of all patients receiving intensive care at RWTH Aachen University Hospital in 2019 for whom aPC consultation was requested. The patient population transferred from the ICU to the PC ward was compared with the non-transferred population. In each case, the primary consultation was evaluated regarding the following factors: question, vigilance, length of time from consultation request to its performance, and primary focus of the question. The question focus was categorized into "symptom control", "counselling" and "transfer" (tick options). In addition, afree text field was available for further notes. Exploration of diagnoses was complemented by accessing the electronic health records. A total of 102 consultation requests from the ICU to the PC ward were evaluated. The morbidity of patients was high, and most patients had at least one of the following diagnoses: pulmonary (62%), cardiovascular (61%), and/or neurological disease (55%). Of the patients 32 (31%) were transferred to the PC ward, among whom weakness (94%), fatigue (77%), anxiety (55%), pain (53%), and dyspnea (48%) were the most frequently noted symptoms. Of the transferred patients 5 (16%) could be discharged to home, nursing home, hospice or other. In total, 35 (34%) of all patients who were seen by palliative care specialists on ICUs in 2019 could be discharged alive. The most frequent reasons for nonadmission were lack of capacity of the PC ward (33%), dying while being on the waiting list (20%), and refusal by the patient (20%). Of the patients, 7 (26%) died within 48 h after they had been transferred to the PC ward. Performed consultation services "symptom control" (χ2 = 10.17; p < 0.05) and "counselling" (χ2 = 12.82; p < 0.001), which were requested by the intensive care physicians, showed asignificant linkage with the respective intervention performed by the palliative care team. On the other hand, no statistically significant difference was found for requested and performed "transfer" of patients from ICUs to PC ward. Comparing the transferred versus non-transferred patient population, asignificantly more frequent transfer of patients with malignant tumors (p = 0.00) was observed. The need for palliative care support in the ICUs exceeded the admission capacity of the PC ward. Future studies should further examine palliative care models in intensive care medicine.

Validation of Wind Turbine Models Based on Test Bench Measurements: A System for Theoretical Representation of the Grid Replica

In recent years, nacelle test benches for wind turbines have been developed internationally. New standards are currently being developed that explicitly refer to the measurement of the electrical properties of wind turbines on these test benches. Thus, they are suitable for measuring the electrical properties required for certification. Another part of the certification is the creation and validation of suitable models of the wind turbine, which are used for stability analyses of the utility grid. Validation requires a suitable model of grid replication on the test benches, which is not yet covered by any applicable standard. Such models should be as simplified a representation of the artificial grid replication as possible to ensure that they are accessible to certification bodies. A model of the grid emulator installed at the CWD of RWTH Aachen University, which was validated with real measurement data, serves as a reference. A step-by-step reduction of the model’s depth up to the system’s technical representation is followed by a model evaluation with respect to the level of detail and an analysis of time and frequency. The evaluation shows that even a highly simplified model consisting of a reference voltage and an impedance replica meets the requirements for the validation of wind turbine models according to IEC 61400-27-2.

Conventional vs. Sutureless Aortic Valve Bioprosthesis: Is Faster Better?

Purpose: The benefits of sutureless compared to conventional aortic valve prosthesis replacement remain controversial. Supposed advantages of sutureless aortic valve replacement include shortened cross-clamp and implantation time, as well as improved overall safety and good post-operative performance. We aimed to compare the early outcomes and performance of sutureless aortic valve replacement (su-AVR) with the sutureless Perceval (Corcym, Milan, Italy) vs. the conventional AVR with a conventional counterpart, in this case, the Labcor Dokimos Plus (LDP) aortic bioprosthesis. Methods: We compared two types of aortic valve prostheses, the sutureless (Corcym, Milan, Italy) and the conventional valve Labcor Dokimos Plus (LDP), implanted between August 2014 and May 2019 in our Department of Cardiac Surgery at RWTH Aachen University Hospital. Data were collected from 141 patients who received the Perceval (Corcym, Milan, Italy) and 138 who received the Labcor Dokimos Plus (LDP) aortic bioprosthesis. After matching the two groups considering STS mortality risk and pre-operative LDH levels, 201 patients were included in our final study cohort. Seventy-one patients (17 from the Perceval group and 54 from the Dokimos group) were excluded due to the lack of complete data, particularly standardized echocardiographic data (n = 71). Primary endpoints were 30-day mortality, length of hospital stay, and pacemaker implantation. Secondary endpoints were echocardiographic parameters, major adverse cardiovascular events, and prosthesis failure (grade II aortic regurgitation, paravalvular leak with reintervention). Results: Bypass and cross-clamp time proved to be shorter in the Perceval group, while hospital stays were longer. The faster implantation had no effect on the 30-day mortality primary endpoint. Transvalvular gradients were significantly higher in the Perceval group, in addition to a smaller effective orifice area. The LDH values were remarkably higher post-operatively in the Perceval group. Conclusions: Regarding the clinical outcomes, Perceval was equivalent and not superior to the Dokimus bioprosthesis. The suitability of a Perceval prosthesis implantation must be determined on a case-by-case basis and reserved for elderly patients with increased comorbidity.

E-Bike Charging Infrastructure in the Workplace—Should Employers Provide It?

Constructing charging infrastructure for e-bikes at home or in other locations is necessary to enable motor support while riding. This paper focuses on charging facilities at work and study locations. It analyzes the charging frequency preference of 281 e-bike commuters who work or study at RWTH Aachen University, using survey data with 1091 choices for hypothetical free charging, as well as the same conditions for hypothetical paid charging. We use a mixed logit model to estimate the factors influencing the charging frequency, focusing on the commuting distance, an e-bike’s resale value, the age of the owner, student status, and employment group. One charging event per day can be expected for four e-bike commuters when free charging is available. In the case of paid charging, there is one charging event per 12 e-bike users. The magnitude of the reduction caused by a charging fee depends on group membership and, probably, on income. Commuting distance only has a statistically significant influence on the charging frequency when charging is free, raising the question of whether charging at work is necessary to cover trip chains that include stops at work. Owners of more expensive e-bikes charge less often, likely due to higher battery capacities, while the influence of age is inconclusive. However, providing charging infrastructure for employees and guests could be used as a low-cost measure to promote cycling among commuters.

EVOLUTION OF RECORDING METHODS: THE AACHEN CATHEDRAL WORLD HERITAGE SITE DOCUMENTATION PROJECT

Abstract. Modern terrestrial laser scanners and photogrammetric imaging systems can provide highly accurate and objective as-built records of existing architectural, engineering, and industrial sites. This comprehensive digital recording benefits culturally significant places like heritage buildings, monuments, and other vital structures. The collected data can be instrumental in various ways, including aiding in conservation, management, monitoring and repair efforts and serving as an educational resource for scholars and the general public. These technical capabilities are especially well-suited for architecturally complex, ornate buildings like the Aachen Cathedral UNESCO World Heritage site. This paper describes the recent recording efforts at the Aachen Cathedral and is a comparative study of the previous documentation work done at the Cologne Cathedral.The 3D documentation of the Aachen Cathedral UNESCO World Heritage Site is an ongoing collaborative project between the Sapienza Università di Roma, Rome, Italy, Robert Gordon University, Aberdeen, Scotland, and in partnership with RWTH Aachen University, and the Dombauhütte Aachen.

Insulin Resistance Is the Main Characteristic of Metabolically Unhealthy Obesity (MUO) Associated with NASH in Patients Undergoing Bariatric Surgery.

(1) Background: Metabolically healthy obesity (MHO) is a concept that applies to obese patients without any elements of metabolic syndrome (metS). In turn, metabolically unhealthy obesity (MUO) defines the presence of elements of metS in obese patients. The components of MUO can be divided into subgroups regarding the elements of inflammation, lipid and glucose metabolism and cardiovascular disease. MUO patients appear to be at greater risk of developing non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) compared to MHO patients. The aim of this study was to evaluate the influence of different MUO components on NAFLD and NASH in patients with morbid obesity undergoing bariatric surgery. (2) Methods: 141 patients undergoing bariatric surgery from September 2015 and October 2021 at RWTH Aachen university hospital (Germany) were included. Patients were evaluated pre-operatively for characteristics of metS and MUO (HbA1c, HOMA, CRP, BMI, fasting glucose, LDL, TG, HDL and the presence of arterial hypertension). Intraoperatively, a liver biopsy was taken from the left liver lobe and evaluated for the presence of NAFLD or NASH. In ordinal regression analyses, different factors were evaluated for their influence on NAFLD and NASH. (3) Results: Mean BMI of the patients was 52.3 kg/m2 (36-74.8, SD 8.4). Together, the parameters HbA1c, HOMA, CRP, BMI, fasting glucose, LDL, TG, HDL and the presence of arterial hypertension accounted for a significant amount of variance in the outcome, with a likelihood ratio of χ2 (9) = 41.547, p < 0.001, for predicting the presence of NASH. Only HOMA was an independent predictor of NASH (B = 0.102, SE = 0.0373, p = 0.007). Evaluation of steatosis showed a similar trend (likelihood ratio χ2 (9) = 40.272, p < 0.001). Independent predictors of steatosis were HbA1c (B = 0.833, SE = 0.343, p = 0.015) and HOMA (B = 0.136, SE = 0.039, p < 0.001). (4) Conclusions: The above-mentioned model, including components of MUO, was significant for diagnosing NASH in patients with morbid obesity undergoing bariatric surgery. Out of the different subitems, HOMA independently predicted the presence of NASH and steatosis, while HbA1c independently predicted steatosis and fibrosis. Taken together, the parameter of glucose metabolism appears to be more accurate for the prediction of NASH than the parameters of lipid metabolism, inflammation or the presence of cardiovascular disease.

A Call to Include Plastics in the Global Environment in the Class of Persistent, Bioaccumulative, and Toxic (PBT) Pollutants.

A Call to Include Plastics in the Global Environment in the Class of Persistent, Bioaccumulative, and Toxic (PBT) Pollutants.

Disconnected Cardiac Autonomic Nerves in Genetic Ganglionic Acetylcholine Receptor Alpha-3 Subunit Deficiency.

HomeHypertensionAhead of PrintDisconnected Cardiac Autonomic Nerves in Genetic Ganglionic Acetylcholine Receptor Alpha-3 Subunit Deficiency No AccessResearch ArticleRequest AccessAboutView PDFSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toNo AccessResearch ArticleRequest AccessDisconnected Cardiac Autonomic Nerves in Genetic Ganglionic Acetylcholine Receptor Alpha-3 Subunit Deficiency Karsten Heusser, Florian Erger, Ulrich Ebner, Barbara Namer, Graeme Eisenhofer, Carl-Albrecht Haensch, Henning Weis, Matthias Schmidt, Alexander Drzezga, Jens Tank, Christian Netzer and Jens Jordan Karsten HeusserKarsten Heusser https://orcid.org/0000-0002-2571-5585 Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany (K.H., H.W., J.T., J.J.). *K. Heusser and F. Erger contributed equally. Search for more papers by this author , Florian ErgerFlorian Erger https://orcid.org/0000-0002-2768-1702 Institute of Human Genetics, Medical Faculty, University of Cologne, Germany (F.E., C.N.). *K. Heusser and F. Erger contributed equally. Search for more papers by this author , Ulrich EbnerUlrich Ebner https://orcid.org/0009-0002-4648-8497 Internal Medicine Practice, Regensburg, Germany (U.E.). Search for more papers by this author , Barbara NamerBarbara Namer https://orcid.org/0000-0001-7500-2842 Institute of Physiology and Pathophysiology, Friedrich Alexander University Erlangen-Nuremberg, Germany (B.N.). Research Group Neuroscience, Interdisciplinary Centre for Clinical Research within the Faculty of Medicine at the RWTH Aachen University, Germany (B.N.). Department for Physiology, Faculty of Medicine at the RWTH Aachen University, Germany (B.N.). Search for more papers by this author , Graeme EisenhoferGraeme Eisenhofer Institute of Clinical Chemistry and Laboratory Medicine, University Hospital Carl Gustav Carus, Medical Faculty, Technical University Dresden, Germany. (G.E.) University Hospital Carl Gustav Carus, Medical Faculty Carl Gustav Carus and Department of Medicine III, University Hospital Carl Gustav Carus, Medical Faculty, Technical University Dresden, Germany. (G.E.) Search for more papers by this author , Carl-Albrecht HaenschCarl-Albrecht Haensch https://orcid.org/0000-0001-6479-0265 Kliniken Maria Hilf Mönchengladbach, Autonomic Laboratory, Department of Neurology, Faculty of Health, University of Witten/Herdecke, Mönchengladbach, Germany (C.-A.H.). Search for more papers by this author , Henning WeisHenning Weis https://orcid.org/0000-0001-8638-3281 Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany (K.H., H.W., J.T., J.J.). Department of Nuclear Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, Germany (H.W., M.S., A.D.). Search for more papers by this author , Matthias SchmidtMatthias Schmidt https://orcid.org/0000-0002-7519-8897 Department of Nuclear Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, Germany (H.W., M.S., A.D.). Search for more papers by this author , Alexander DrzezgaAlexander Drzezga Department of Nuclear Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, Germany (H.W., M.S., A.D.). Search for more papers by this author , Jens TankJens Tank https://orcid.org/0000-0002-5672-1187 Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany (K.H., H.W., J.T., J.J.). Search for more papers by this author , Christian NetzerChristian Netzer Institute of Human Genetics, Medical Faculty, University of Cologne, Germany (F.E., C.N.). †C. Netzer and J. Jordan contributed equally. Search for more papers by this author and Jens JordanJens Jordan Correspondence to: Jens Jordan, Institute for Aerospace Medicine, Linder Hoehe, 51147 Cologne, Germany. Email E-mail Address: [email protected] https://orcid.org/0000-0003-4518-0706 Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany (K.H., H.W., J.T., J.J.). †C. Netzer and J. Jordan contributed equally. Search for more papers by this author Originally published10 May 2023https://doi.org/10.1161/HYPERTENSIONAHA.123.21172Hypertension. 2023;0Footnotes*K. Heusser and F. Erger contributed equally.†C. Netzer and J. Jordan contributed equally.For Sources of Funding and Disclosures, see page XXX.Correspondence to: Jens Jordan, Institute for Aerospace Medicine, Linder Hoehe, 51147 Cologne, Germany. Email jens.[email protected]de Previous Back to top Next FiguresReferencesRelatedDetails Advertisement Article InformationMetrics © 2023 American Heart Association, Inc.https://doi.org/10.1161/HYPERTENSIONAHA.123.21172PMID: 37161764 Originally publishedMay 10, 2023 KeywordsCHRNA3autonomic failureganglionic acetylcholine receptorsympathetic nervous systemPDF download Advertisement SubjectsAutonomic Nervous SystemGeneticsMechanismsNuclear Cardiology and PETPathophysiology

Extension of an In Vitro Spine Test Rig to Track Load‐dependent Biomechanics of the Lumbar Spine under Physiological Conditions

AbstractLow back pain is a major cause of chronic health problems and is often related to loading history. A test rig was developed at the Institute of General Mechanics, RWTH Aachen University to investigate the influence of duration and intensity of spinal loading using in vitro experiments on spinal cadavers. In this work, several extensions of this spine test rig are presented: (1) a hydraulic cylinder with a force measuring unit was added to apply axial compression; (2) a new follower load principle system was developed to achieve uniform compression of the naturally curved spine; (3) the specimen is immersed in phosphate‐buffered saline with protease inhibitors during the testing period to allow osmotic interactions on the one hand and the investigation of the influence of different loading and rest cycles on the other hand; (4) a fiber‐optic pressure measurement system was added to successfully measure the intradiscal pressure during the test series. The first results obtained using these test rig extensions and the new pressure measurement system show their functionality. The new test rig enables the investigation of a wide range of load scenarios and further measurement parameters.

Onboard train speed optimization for energy saving using the prediction of block clearing times under real-time rescheduling

Energy-saving driving is crucial during railway operation, especially in case of disturbances that require timetable rescheduling. This paper presents a method for the dynamic onboard tuning of energy-efficient speed profiles after the real-time train rescheduling process under a fixed block signaling system for mixed traffic. Similar to the idea of connected driver advisory systems, trains constantly communicate with a central traffic management system. After the rescheduling process, this system provides recommended time corridors for the passing of block signals that depend on the predicted clearing times of the block sections. These recommendations are then used for individual energy optimization of single train runs by avoiding unnecessary braking in front of block signals and maximizing cruising distances. The method is tested and evaluated on a representative line segment of the ELVA, the Railway Signaling Lab at RWTH Aachen University under realistic conditions. Energy consumptions are compared for different prediction time horizons at which the recommendations are available to the train's onboard system. In the examined test case of two trains, the energy-consumption could be decreased by up to 53% compared to operation without any rescheduling system. Thus, the proposed method is able to reduce energy consumption significantly.

2023 TERMIS – AMERICAS Conference &amp; Exhibition Boston Marriott Copley Place April 11–14, 2023

2023 TERMIS – AMERICAS Conference &amp; Exhibition Boston Marriott Copley Place April 11–14, 2023

A Reactive Molecular Dynamics Study of Chlorinated Organic Compounds. Part II: A ChemTraYzer Study of Chlorinated Dibenzofuran Formation and Decomposition Processes.

The front cover artwork is provided by Prof. K. Leonhard's group at RWTH Aachen University. The image shows ChemTraYzer, a virtual robot, while analyzing the reaction network related to the formation and oxidation of Chloro-Dibenzofuranes. Read the full text of the Research Article at 10.1002/cphc.202200783.