Refine
Year of publication
- 2022 (133) (remove)
Institute
- Fachbereich Medizintechnik und Technomathematik (41)
- Fachbereich Energietechnik (29)
- IfB - Institut für Bioengineering (27)
- ECSM European Center for Sustainable Mobility (16)
- Fachbereich Chemie und Biotechnologie (16)
- Solar-Institut Jülich (14)
- Fachbereich Elektrotechnik und Informationstechnik (12)
- Fachbereich Luft- und Raumfahrttechnik (11)
- INB - Institut für Nano- und Biotechnologien (11)
- Kommission für Forschung und Entwicklung (10)
Has Fulltext
- no (133) (remove)
Language
- English (133) (remove)
Document Type
- Article (69)
- Conference Proceeding (46)
- Part of a Book (9)
- Conference: Meeting Abstract (5)
- Other (2)
- Book (1)
- Conference Poster (1)
Keywords
- Concentrated solar power (3)
- Energy storage (3)
- Hybrid energy system (3)
- Biocomposites (2)
- Chemometrics (2)
- Digital Twin (2)
- Earthquake (2)
- Electricity generation (2)
- Gamification (2)
- Heparin (2)
- IO-Link (2)
- NMR spectroscopy (2)
- Natural fibres (2)
- Polymer-matrix composites (2)
- Power plants (2)
- Seismic design (2)
- Seismic loading (2)
- Solar thermal technologies (2)
- Stress concentrations (2)
- damage (2)
- seismic design (2)
- 10BASE-T1L (1)
- Additive Manufacturing (1)
- Additive manufacturing (1)
- Alzheimer's disease (1)
- Analogue Environments (1)
- Angle Sensor (1)
- Arduino (1)
- Artificial Intelligence (1)
- Artificial intelligence (1)
- Assembly (1)
- Asset Administration Shell (1)
- Associated liquids (1)
- Automated driving (1)
- Automotive application (1)
- Behaviour factor q (1)
- Benchmark (1)
- Binder Jetting (1)
- Biomass (1)
- Biomechanical simulation (1)
- Bootstrapping (1)
- Boundary integral equations (1)
- CAV (1)
- Camera system (1)
- Case Study (1)
- Categorial variable (1)
- Cementoblast (1)
- Central receiver power plant (1)
- Central receiver system (1)
- Ceramics (1)
- Challenges (1)
- Chance constrained programming (1)
- Change management (1)
- Civil engineering (1)
- Clinical decision support systems (1)
- Cloud passages (1)
- Clustering (1)
- Collective risk model (1)
- Compression (1)
- Concentrated solar collector (1)
- Concentrated systems (1)
- Concomitant (1)
- Conductive boundary condition (1)
- Conpot (1)
- Control optimization (1)
- Crude heparin (1)
- Cryobot (1)
- DNI forecast (1)
- DNI forecasting (1)
- Decoupling (1)
- Digital Twin Evolution (1)
- Digital Twins (1)
- Direct normal irradiance forecast (1)
- Directed Energy Deposition (1)
- Diversity management (1)
- Drinfeld modules (1)
- Dynamic simulation (1)
- EN 1998-4 (1)
- ES-FEM (1)
- ESHM20, industrial facilities (1)
- Electrical Flight (1)
- Empirical process (1)
- Energy system (1)
- Erasmus+ United (1)
- Ethernet (1)
- Evolution of damage (1)
- Explainability (1)
- Extension fracture (1)
- Extension strain criterion (1)
- FGF23 (1)
- FPGA (1)
- FS-FEM (1)
- Feature selection (1)
- Field device (1)
- Finite element analysis (1)
- Finite element analysis (FEA) (1)
- Flight Mechanics (1)
- Flight Tests (1)
- Forces (1)
- Fracture classification (1)
- Fracture configuration (1)
- Fracture simulation (1)
- Gas turbine (1)
- Genetic algorithm (1)
- Global change (1)
- Guidelines (1)
- Haemodialysis (1)
- Handbike (1)
- Hazard assessment (1)
- Heliostat Field Calibration (1)
- Heliostats (1)
- Heterostructure (1)
- Higher derivations (1)
- Humidity (1)
- Hybridization (1)
- ICS (1)
- INSYSME (1)
- IR spectroscopy (1)
- Ice Melting (1)
- Icy Moons (1)
- Image Reconstruction (1)
- Imaging (1)
- In-plane load (1)
- In-plane performance, isolation (1)
- Inclusive work climate (1)
- Incremental Encoder (1)
- Independence test (1)
- Industrial Communication (1)
- Industrial facilities (1)
- Industry 4.0 (1)
- Infill wall design (1)
- Inflight Regeneration, Recuperation (1)
- Information Extraction (1)
- Inorganic ions (1)
- Instructional design (1)
- Interaction (1)
- Interstellar objects (1)
- Inverse spectral problem (1)
- Ions (1)
- Justice (1)
- Kalman filter (1)
- Klotho (1)
- Knowledge Transfer (1)
- L-PBF (1)
- LPBF (1)
- Landslide tsunamis (1)
- Large scale tests (1)
- Laser-Powder Bed Fusion (1)
- Level system (1)
- Lidar (1)
- Limit analysis (1)
- Linear elastic analysis (1)
- Machine Learning (1)
- Machine learning (1)
- Malaysian automotive industry (1)
- Masonry infill (1)
- Measurement models (1)
- Measurement uncertainty (1)
- Measuring instruments (1)
- Mechanotransduction (1)
- Medical AI (1)
- Melting Efficiency (1)
- Melting Performance (1)
- Melting Probe (1)
- Metascintillator (1)
- Microcirculation (1)
- Mild cognitive impairment (1)
- Missions (1)
- Mixed integer linear programming (MILP) (1)
- Modelling (1)
- Modern constructions (1)
- Mohr–Coulomb criterion (1)
- Molecular modelling (1)
- Molecular weight determination (1)
- Molten salt receiver (1)
- Molten salt receiver system (1)
- Molten salt receiver system, (1)
- Molten salt solar tower (1)
- Monte Carlo Tree Search (1)
- Morphing (1)
- Multi-agent Systems (1)
- Multiple TOF kernels (1)
- Myocardial infarction and cardiac death (1)
- NMR (1)
- Natural Language Processing (1)
- Niacin (1)
- Normative standards (1)
- Nowcasting (1)
- Numerical modelling (1)
- Ocean Worlds (1)
- Organizational culture (1)
- Out-of-plane load (1)
- Overland flow (1)
- PEM fuel cells (1)
- PLS-regression (1)
- PTC (1)
- PTH (1)
- Parabolic trough collector (1)
- Paralympic sport (1)
- Perception (1)
- Periods (1)
- Phosphate (1)
- Photovoltaics (1)
- Position Encoder (1)
- Powder Material (1)
- Power conversion systems (1)
- Probability distribution mapping (1)
- Process mining (1)
- Process prediction (1)
- Profile Extraction (1)
- Propeller Aerodynamics (1)
- Proper Orthogonal Decomposition (1)
- Proximal humerus fracture (1)
- Psychological concepts (1)
- Pulsations (1)
- Q-criterion (1)
- Quadrocopter (1)
- Quality control (1)
- Quantum Computing (1)
- Quantum Machine Learning (1)
- Quantum chemistry (1)
- Rapid-prototyping (1)
- Reinforced concrete frame (1)
- Reliability of structures (1)
- Renewable energy (1)
- Retinal vessel analysis (1)
- Retinal vessels (1)
- Riboflavin (1)
- Rotational Encoder (1)
- Rotator cuff (1)
- S-FEM (1)
- SME (1)
- Self-driving (1)
- Sensors (1)
- Shakedown analysis (1)
- Shoulder (1)
- Solar concentration (1)
- Solar dish (1)
- Solar irradiance (1)
- Solitary waves (1)
- Standardization (1)
- Star design (1)
- Stochastic programming (1)
- Structural design (1)
- Structural health monitoring (1)
- Support System (1)
- TOF PET (1)
- Tanks (1)
- Tension (1)
- Text Mining (1)
- Thermal Energy Storage (1)
- Thiamine (1)
- Time-series aggregation (1)
- Tobacco mosaic virus (1)
- Training (1)
- Trajectories (1)
- Transcendence (1)
- Transient flux distribution (1)
- Transmission eigenvalues (1)
- Two-phase modelling (1)
- Typical periods (1)
- UAV (1)
- USP (1)
- UTeM Engineering Knowledge Transfer Unit (1)
- Uncertainty analysis (1)
- Unmanned aerial vehicle (1)
- Unreinforced masonry buildings (1)
- User study (1)
- Vasomotions (1)
- Virtual reality (1)
- Vitamin A (1)
- Vitamin B (1)
- Vitamin D (1)
- Wiegand Effect (1)
- Window opening (1)
- acetoin (1)
- additive manufacturing (1)
- adipose-derived stromal cells (ASCs) (1)
- aminooctanethiol (1)
- anaesthetic complications (1)
- anisotropy (1)
- aortic perfusion (1)
- aseptic parameters (1)
- automated vehicles (1)
- aviation application (1)
- bacterial cellulose (1)
- batteries and fuel cells (1)
- behaviour factor q (1)
- bi-enzyme biosensor (1)
- biaxial tensile experiment (1)
- biopotential electrodes (1)
- biosensors (1)
- body imaging at 7 T MRI (1)
- bootstrap (1)
- borefields (1)
- borehole disposal (1)
- bullying (1)
- capacitive field-effect biosensor (1)
- capacitive field-effect sensor (1)
- capacitive model (1)
- cell aerosolization (1)
- cell atomization (1)
- cerebral small vessel disease (1)
- chance constrained programming (1)
- coculture (1)
- cognitive impairment (1)
- coherent structures (1)
- combustor development (1)
- competence developing games (1)
- computational fluid dynamics analysis (1)
- connected automated vehicles (1)
- constitutive modeling (1)
- control system (1)
- correlation (1)
- crystallization (1)
- cyber physical production system (1)
- cyber-physical production system (1)
- cybersecurity (1)
- dental trauma (1)
- dialysis (1)
- difficult airway (1)
- digital shadow (1)
- digital twin (1)
- disposal facility (1)
- distorted element (1)
- double-lumen tube intubation (1)
- electrolyte-insulator-semiconductor capacitors (1)
- electrospinning (1)
- emission (1)
- endoluminal (1)
- energy (1)
- enzyme immobilization (1)
- enzyme-logic gate (1)
- exopolysaccharides (1)
- experimental evaluation (1)
- extracorporeal membrane oxygenation (1)
- eye movement modelling examples (1)
- fibers (1)
- field-effect sensor (1)
- force generation (1)
- forehead EEG (1)
- frequency mixing magnetic detection (1)
- fuel cell systems (1)
- fuels (1)
- fused filament fabrication (1)
- gaseous hydrogen peroxide (1)
- geological disposal (1)
- geothermal (1)
- gold nanoparticles (1)
- health management systems (1)
- high-intensity exercise (1)
- honeynet (1)
- honeypot (1)
- human digital shadow (1)
- human factors (1)
- human-machine interface (1)
- hydraulic modelling (1)
- hydrogen (1)
- hyperelastic (1)
- ignition (1)
- impedance spectroscopy (1)
- in-ear EEG (1)
- industrial gas turbine (1)
- irradiation (1)
- lessons learned (1)
- limit analysis (1)
- linear elastic analysis; (1)
- magnetic nanoparticles (1)
- magnetic sensors (1)
- metrological characterization (1)
- microplasma (1)
- microwave (MW) plasma (1)
- model performance (1)
- modern constructions (1)
- multi-sensing platform (1)
- muscle fascicle behavior (1)
- nanoparticle coverage (1)
- non-simplex S-FEM elements (1)
- nuclear waste (1)
- passive inter-modulation (1)
- penicillinase (1)
- performance testing (1)
- plasma jet (1)
- policy recommendations (1)
- polyetheretherketone (1)
- porous materials (1)
- power integrity (1)
- prebiotic (1)
- pullulan (1)
- rapid tooling (1)
- recommendations for actions (1)
- reliability of structures (1)
- requirements (1)
- retention time (1)
- retinal vessels (1)
- sEMG (1)
- safety control (1)
- seismic hazard (1)
- shakedown analysis (1)
- signal integrity (1)
- simulation (1)
- sizing (1)
- smooth muscle contraction (1)
- software engineering (1)
- spore kill rate (1)
- sterility (1)
- stochastic programming (1)
- strain energy function (1)
- survival (1)
- systematic literature review (1)
- t-modules (1)
- technology transfer (1)
- tendon rupture (1)
- thermal dose (1)
- tissue temperature (1)
- tobacco mosaic virus (TMV) (1)
- transmit antenna arrays (1)
- tri-lineage differentiation (1)
- twin-fluid atomizer (1)
- ultrasound imaging (1)
- unreinforced masonry buildings (1)
- urease (1)
- video learning (1)
- videolaryngoscopy (1)
- virgin passive (1)
- viscoelasticity (1)
- walking gait (1)
The recent amendment to the Ethernet physical layer known as the IEEE 802.3cg specification, allows to connect devices up to a distance of one kilometer and delivers a maximum of 60 watts of power over a twisted pair of wires. This new standard, also known as 10BASE-TIL, promises to overcome the limits of current physical layers used for field devices and bring them a step closer to Ethernet-based applications. The main advantage of 10BASE- TIL is that it can deliver power and data over the same line over a long distance, where traditional solutions (e.g., CAN, IO-Link, HART) fall short and cannot match its 10 Mbps bandwidth. Due to its recentness, IOBASE- TIL is still not integrated into field devices and it has been less than two years since silicon manufacturers released the first Ethernet-PHY chips. In this paper, we present a design proposal on how field devices could be integrated into a IOBASE-TIL smart switch that allows plug-and-play connectivity for sensors and actuators and is compliant with the Industry 4.0 vision. Instead of presenting a new field-level protocol for this work, we have decided to adopt the IO-Link specification which already includes a plug-and-play approach with features such as diagnosis and device configuration. The main objective of this work is to explore how field devices could be integrated into 10BASE-TIL Ethernet, its adaption with a well-known protocol, and its integration with Industry 4.0 technologies.
Orthodontic treatments are concomitant with mechanical forces and thereby cause teeth movements. The applied forces are transmitted to the tooth root and the periodontal ligaments which is compressed on one side and tensed up on the other side. Indeed, strong forces can lead to tooth root resorption and the crown-to-tooth ratio is reduced with the potential for significant clinical impact. The cementum, which covers the tooth root, is a thin mineralized tissue of the periodontium that connects the periodontal ligament with the tooth and is build up by cementoblasts. The impact of tension and compression on these cells is investigated in several in vivo and in vitro studies demonstrating differences in protein expression and signaling pathways. In summary, osteogenic marker changes indicate that cyclic tensile forces support whereas static tension inhibits cementogenesis. Furthermore, cementogenesis experiences the same protein expression changes in static conditions as static tension, but cyclic compression leads to the exact opposite of cyclic tension. Consistent with marker expression changes, the singaling pathways of Wnt/ß-catenin and RANKL/OPG show that tissue compression leads to cementum degradation and tension forces to cementogenesis. However, the cementum, and in particular its cementoblasts, remain a research area which should be explored in more detail to understand the underlying mechanism of bone resorption and remodeling after orthodontic treatments.
Automated driving is now possible in diverse road and traffic conditions. However, there are still situations that automated vehicles cannot handle safely and efficiently. In this case, a Transition of Control (ToC) is necessary so that the driver takes control of the driving. Executing a ToC requires the driver to get full situation awareness of the driving environment. If the driver fails to get back the control in a limited time, a Minimum Risk Maneuver (MRM) is executed to bring the vehicle into a safe state (e.g., decelerating to full stop). The execution of ToCs requires some time and can cause traffic disruption and safety risks that increase if several vehicles execute ToCs/MRMs at similar times and in the same area. This study proposes to use novel C-ITS traffic management measures where the infrastructure exploits V2X communications to assist Connected and Automated Vehicles (CAVs) in the execution of ToCs. The infrastructure can suggest a spatial distribution of ToCs, and inform vehicles of the locations where they could execute a safe stop in case of MRM. This paper reports the first field operational tests that validate the feasibility and quantify the benefits of the proposed infrastructure-assisted ToC and MRM management. The paper also presents the CAV and roadside infrastructure prototypes implemented and used in the trials. The conducted field trials demonstrate that infrastructure-assisted traffic management solutions can reduce safety risks and traffic disruptions.
Edge-based and face-based smoothed finite element methods (ES-FEM and FS-FEM, respectively) are modified versions of the finite element method allowing to achieve more accurate results and to reduce sensitivity to mesh distortion, at least for linear elements. These properties make the two methods very attractive. However, their implementation in a standard finite element code is nontrivial because it requires heavy and extensive modifications to the code architecture. In this article, we present an element-based formulation of ES-FEM and FS-FEM methods allowing to implement the two methods in a standard finite element code with no modifications to its architecture. Moreover, the element-based formulation permits to easily manage any type of element, especially in 3D models where, to the best of the authors' knowledge, only tetrahedral elements are used in FS-FEM applications found in the literature. Shape functions for non-simplex 3D elements are proposed in order to apply FS-FEM to any standard finite element.
Non-intrusive measuring techniques have attained a lot of interest in relation to both hydraulic modeling and prototype applications. Complimenting acoustic techniques, significant progress has been made for the development of new optical methods. Computer vision techniques can help to extract new information, e. g. high-resolution velocity and depth data, from videos captured with relatively inexpensive, consumer-grade cameras. Depth cameras are sensors providing information on the distance between the camera and observed features. Currently, sensors with different working principles are available. Stereoscopic systems reference physical image features (passive system) from two perspectives; in order to enhance the number of features and improve the results, a sensor may also estimate the disparity from a detected light to its original projection (active stereo system). In the current study, the RGB-D camera Intel RealSense D435, working on such stereo vision principle, is used in different, typical hydraulic modeling applications. All tests have been conducted at the Utah Water Research Laboratory. This paper will demonstrate the performance and limitations of the RGB-D sensor, installed as a single camera and as camera arrays, applied to 1) detect the free surface for highly turbulent, aerated hydraulic jumps, for free-falling jets and for an energy dissipation basin downstream of a labyrinth weir and 2) to monitor local scours upstream and downstream of a Piano Key Weir. It is intended to share the authors’ experiences with respect to camera settings, calibration, lightning conditions and other requirements in order to promote this useful, easily accessible device. Results will be compared to data from classical instrumentation and the literature. It will be shown that even in difficult application, e. g. the detection of a highly turbulent, fluctuating free-surface, the RGB-D sensor may yield similar accuracy as classical, intrusive probes.
Additive Manufacturing (AM) of metallic workpieces faces a continuously rising technological relevance and market size. Producing complex or highly strained unique workpieces is a significant field of application, making AM highly relevant for tool components. Its successful economic application requires systematic workpiece based decisions and optimizations. Considering geometric and technological requirements as well as the necessary post-processing makes deciding effortful and requires in-depth knowledge. As design is usually adjusted to established manufacturing, associated technological and strategic potentials are often neglected. To embed AM in a future proof industrial environment, software-based self-learning tools are necessary. Integrated into production planning, they enable companies to unlock the potentials of AM efficiently. This paper presents an appropriate methodology for the analysis of process-specific AM-eligibility and optimization potential, added up by concrete optimization proposals. For an integrated workpiece characterization, proven methods are enlarged by tooling-specific figures.
The first stage of the approach specifies the model’s initialization. A learning set of tooling components is described using the developed key figure system. Based on this, a set of applicable rules for workpiece-specific result determination is generated through clustering and expert evaluation. Within the following application stage, strategic orientation is quantified and workpieces of interest are described using the developed key figures. Subsequently, the retrieved information is used for automatically generating specific recommendations relying on the generated ruleset of stage one. Finally, actual experiences regarding the recommendations are gathered within stage three. Statistic learning transfers those to the generated ruleset leading to a continuously deepening knowledge base. This process enables a steady improvement in output quality.
This paper considers a paired data framework and discusses the question of marginal homogeneity of bivariate high-dimensional or functional data. The related testing problem can be endowed into a more general setting for paired random variables taking values in a general Hilbert space. To address this problem, a Cramér–von-Mises type test statistic is applied and a bootstrap procedure is suggested to obtain critical values and finally a consistent test. The desired properties of a bootstrap test can be derived that are asymptotic exactness under the null hypothesis and consistency under alternatives. Simulations show the quality of the test in the finite sample case. A possible application is the comparison of two possibly dependent stock market returns based on functional data. The approach is demonstrated based on historical data for different stock market indices.
Process mining gets more and more attention even outside large enterprises and can be a major benefit for small and medium sized enterprises (SMEs) to gain competitive advantages. Applying process mining is challenging, particularly for SMEs because they have less resources and process maturity. So far, IS researchers analyzed process mining challenges with a focus on larger companies. This paper investigates the application of process mining by means of a case study and sheds light into the particular challenges of an IT SME. The results reveal 13 SME process mining challenges and seven guidelines to address them. In this way, the paper contributes to the understanding of process mining application in SME and shows similarities and differences to larger companies.
A Gamified Information System (GIS) implements game concepts and elements, such as affordances and game design principles to motivate people. Based on the idea to develop a GIS to increase the motivation of software developers to perform software quality tasks, the research work at hand aims at investigating relevant requirements from that target group. Therefore, 14 interviews with software development experts are conducted and analyzed. According to the results, software developers prefer the affordances points, narrative storytelling in a multiplayer and a round-based setting. Furthermore, six design principles for the development of a GIS are derived.
Eye movement modelling examples (EMME) are instructional videos that display a
teacher’s eye movements as “gaze cursor” (e.g. a moving dot) superimposed on the
learning task. This study investigated if previous findings on the beneficial effects of EMME would extend to online lecture videos and compared the effects of displaying the teacher’s gaze cursor with displaying the more traditional mouse cursor as a tool to guide learners’ attention. Novices (N = 124) studied a pre-recorded video lecture on how to model business processes in a 2 (mouse cursor absent/present) × 2 (gaze cursor absent/present) between-subjects design. Unexpectedly, we did not find significant effects of the presence of gaze or mouse cursors on mental effort and learning. However, participants who watched videos with the gaze cursor found it easier to follow the teacher. Overall, participants responded positively to the gaze cursor, especially when the mouse cursor was not displayed in the video.
Biomedical applications of magnetic nanoparticles (MNP) fundamentally rely on the particles’ magnetic relaxation as a response to an alternating magnetic field. The magnetic relaxation complexly depends on the interplay of MNP magnetic and physical properties with the applied field parameters. It is commonly accepted that particle core size is a major contributor to signal generation in all the above applications, however, most MNP samples comprise broad distribution spanning nm and more. Therefore, precise knowledge of the exact contribution of individual core sizes to signal generation is desired for optimal MNP design generally for each application. Specifically, we present a magnetic relaxation simulation-driven analysis of experimental frequency mixing magnetic detection (FMMD) for biosensing to quantify the contributions of individual core size fractions towards signal generation. Applying our method to two different experimental MNP systems, we found the most dominant contributions from approx. 20 nm sized particles in the two independent MNP systems. Additional comparison between freely suspended and immobilized MNP also reveals insight in the MNP microstructure, allowing to use FMMD for MNP characterization, as well as to further fine-tune its applicability in biosensing.
The fourth industrial revolution presents a multitude of challenges for industries, one of which being the increased flexibility required of manufacturing lines as a result of increased consumer demand for individualised products. One solution to tackle this challenge is the digital twin, more specifically the standardised model of a digital twin also known as the asset administration shell. The standardisation of an industry wide communications tool is a critical step in enabling inter-company operations. This paper discusses the current state of asset administration shells, the frameworks used to host them and their problems that need to be addressed. To tackle these issues, we propose an event-based server capable of drastically reducing response times between assets and asset administration shells and a multi-agent system used for the orchestration and deployment of the shells in the field.
The subtilase family (S8), a member of the clan SB of serine proteases are ubiquitous in all kingdoms of life and fulfil different physiological functions. Subtilases are divided in several groups and especially subtilisins are of interest as they are used in various industrial sectors. Therefore, we searched for new subtilisin sequences of the family Bacillaceae using a data mining approach. The obtained 1,400 sequences were phylogenetically classified in the context of the subtilase family. This required an updated comprehensive overview of the different groups within this family. To fill this gap, we conducted a phylogenetic survey of the S8 family with characterised holotypes derived from the MEROPS database. The analysis revealed the presence of eight previously uncharacterised groups and 13 subgroups within the S8 family. The sequences that emerged from the data mining with the set filter parameters were mainly assigned to the subtilisin subgroups of true subtilisins, high-alkaline subtilisins, and phylogenetically intermediate subtilisins and represent an excellent source for new subtilisin candidates.
This dataset was acquired at field tests of the steerable ice-melting probe "EnEx-IceMole" (Dachwald et al., 2014). A field test in summer 2014 was used to test the melting probe's system, before the probe was shipped to Antarctica, where, in international cooperation with the MIDGE project, the objective of a sampling mission in the southern hemisphere summer 2014/2015 was to return a clean englacial sample from the subglacial brine reservoir supplying the Blood Falls at Taylor Glacier (Badgeley et al., 2017, German et al., 2021).
The standardized log-files generated by the IceMole during melting operation include more than 100 operational parameters, housekeeping information, and error states, which are reported to the base station in intervals of 4 s. Occasional packet loss in data transmission resulted in a sparse number of increased sampling intervals, which where compensated for by linear interpolation during post processing. The presented dataset is based on a subset of this data: The penetration distance is calculated based on the ice screw drive encoder signal, providing the rate of rotation, and the screw's thread pitch. The melting speed is calculated from the same data, assuming the rate of rotation to be constant over one sampling interval. The contact force is calculated from the longitudinal screw force, which es measured by strain gauges. The used heating power is calculated from binary states of all heating elements, which can only be either switched on or off. Temperatures are measured at each heating element and averaged for three zones (melting head, side-wall heaters and back-plate heaters).
In this study, the performance of an integrated body-imaging array for 7 T with 32 radiofrequency (RF) channels under consideration of local specific absorption rate (SAR), tissue temperature, and thermal dose limits was evaluated and the imaging performance was compared with a clinical 3 T body coil.
Thirty-two transmit elements were placed in three rings between the bore liner and RF shield of the gradient coil. Slice-selective RF pulse optimizations for B1 shimming and spokes were performed for differently oriented slices in the body under consideration of realistic constraints for power and local SAR. To improve the B1+ homogeneity, safety assessments based on temperature and thermal dose were performed to possibly allow for higher input power for the pulse optimization than permissible with SAR limits.
The results showed that using two spokes, the 7 T array outperformed the 3 T birdcage in all the considered regions of interest. However, a significantly higher SAR or lower duty cycle at 7 T is necessary in some cases to achieve similar B1+ homogeneity as at 3 T. The homogeneity in up to 50 cm-long coronal slices can particularly benefit from the high RF shim performance provided by the 32 RF channels. The thermal dose approach increases the allowable input power and the corresponding local SAR, in one example up to 100 W/kg, without limiting the exposure time necessary for an MR examination.
In conclusion, the integrated antenna array at 7 T enables a clinical workflow for body imaging and comparable imaging performance to a conventional 3 T clinical body coil.
Flexible fuel operation of a Dry-Low-NOx Micromix Combustor with Variable Hydrogen Methane Mixture
(2022)
The role of hydrogen (H2) as a carbon-free energy carrier is discussed since decades for reducing greenhouse gas emissions. As bridge technology towards a hydrogen-based energy supply, fuel mixtures of natural gas or methane (CH4) and hydrogen are possible.
The paper presents the first test results of a low-emission Micromix combustor designed for flexible-fuel operation with variable H2/CH4 mixtures. The numerical and experimental approach for considering variable fuel mixtures instead of recently investigated pure hydrogen is described.
In the experimental studies, a first generation FuelFlex Micromix combustor geometry is tested at atmospheric pressure at gas turbine operating conditions corresponding to part- and full-load. The H2/CH4 fuel mixture composition is varied between 57 and 100 vol.% hydrogen content.
Despite the challenges flexible-fuel operation poses onto the design of a combustion system, the evaluated FuelFlex Micromix prototype shows a significant low NOx performance
In general aviation, too, it is desirable to be able to operate existing internal combustion engines with fuels that produce less CO₂ than Avgas 100LL being widely used today It can be assumed that, in comparison, the fuels CNG, LPG or LNG, which are gaseous under normal conditions, produce significantly lower emissions. Necessary propulsion system adaptations were investigated as part of a research project at Aachen University of Applied Sciences.
Inference on the basis of high-dimensional and functional data are two topics which are discussed frequently in the current statistical literature. A possibility to include both topics in a single approach is working on a very general space for the underlying observations, such as a separable Hilbert space. We propose a general method for consistently hypothesis testing on the basis of random variables with values in separable Hilbert spaces. We avoid concerns with the curse of dimensionality due to a projection idea. We apply well-known test statistics from nonparametric inference to the projected data and integrate over all projections from a specific set and with respect to suitable probability measures. In contrast to classical methods, which are applicable for real-valued random variables or random vectors of dimensions lower than the sample size, the tests can be applied to random vectors of dimensions larger than the sample size or even to functional and high-dimensional data. In general, resampling procedures such as bootstrap or permutation are suitable to determine critical values. The idea can be extended to the case of incomplete observations. Moreover, we develop an efficient algorithm for implementing the method. Examples are given for testing goodness-of-fit in a one-sample situation in [1] or for testing marginal homogeneity on the basis of a paired sample in [2]. Here, the test statistics in use can be seen as generalizations of the well-known Cramérvon-Mises test statistics in the one-sample and two-samples case. The treatment of other testing problems is possible as well. By using the theory of U-statistics, for instance, asymptotic null distributions of the test statistics are obtained as the sample size tends to infinity. Standard continuity assumptions ensure the asymptotic exactness of the tests under the null hypothesis and that the tests detect any alternative in the limit. Simulation studies demonstrate size and power of the tests in the finite sample case, confirm the theoretical findings, and are used for the comparison with concurring procedures. A possible application of the general approach is inference for stock market returns, also in high data frequencies. In the field of empirical finance, statistical inference of stock market prices usually takes place on the basis of related log-returns as data. In the classical models for stock prices, i.e., the exponential Lévy model, Black-Scholes model, and Merton model, properties such as independence and stationarity of the increments ensure an independent and identically structure of the data. Specific trends during certain periods of the stock price processes can cause complications in this regard. In fact, our approach can compensate those effects by the treatment of the log-returns as random vectors or even as functional data.
On the basis of independent and identically distributed bivariate random vectors, where the components are categorial and continuous variables, respectively, the related concomitants, also called induced order statistic, are considered. The main theoretical result is a functional central limit theorem for the empirical process of the concomitants in a triangular array setting. A natural application is hypothesis testing. An independence test and a two-sample test are investigated in detail. The fairly general setting enables limit results under local alternatives and bootstrap samples. For the comparison with existing tests from the literature simulation studies are conducted. The empirical results obtained confirm the theoretical findings.