Fachbereich Ingenieurwissenschaften und Kommunikation
Refine
H-BRS Bibliography
- yes (140)
Departments, institutes and facilities
- Fachbereich Ingenieurwissenschaften und Kommunikation (140)
- Institut für Technik, Ressourcenschonung und Energieeffizienz (TREE) (88)
- Fachbereich Informatik (14)
- Internationales Zentrum für Nachhaltige Entwicklung (IZNE) (13)
- Institute of Visual Computing (IVC) (6)
- Institut für funktionale Gen-Analytik (IFGA) (4)
- Fachbereich Angewandte Naturwissenschaften (2)
- Institut für Sicherheitsforschung (ISF) (2)
- Fachbereich Sozialpolitik und Soziale Sicherung (1)
- Institut für KI und Autonome Systeme (A2S) (1)
Document Type
- Article (140) (remove)
Year of publication
Language
- English (140) (remove)
Keywords
- ISM: molecules (6)
- West Africa (4)
- Hydrogen storage (3)
- Lattice Boltzmann Method (3)
- Optimization (3)
- error analysis (3)
- magnetic resonance spectrometers auxiliary equipment (3)
- polyethylene (3)
- pulsars: general (3)
- radiowave spectrometers (3)
- stars: formation (3)
- submillimeter wave microwave (3)
- techniques (3)
- Exchangeable pairs (2)
- Extrusion blow molding (2)
- Force field (2)
- Galaxy: centre (2)
- Global horizontal irradiance (2)
- ISM: kinematics (2)
- Radio-frequency (2)
- Semi-Lagrangian (2)
- Stein’s method (2)
- Topological reduction (2)
- accelerometer (2)
- bolometers (2)
- crystallization (2)
- double pulse test (2)
- dynamics (2)
- energy meteorology (2)
- instrumentation: spectrographs (2)
- ionic liquids (2)
- local chain orientation (2)
- measurement errors (2)
- mesoscale coarse-graining (2)
- microwave spectra (2)
- modeling of complex systems (2)
- power semiconductors (2)
- quantum cascade lasers (2)
- quantum mechanics (2)
- radio lines: ISM (2)
- relaxation (2)
- sensor phenomena and characterization (2)
- shrinkage (2)
- stars: magnetars (2)
- techniques: spectroscopic (2)
- terahertz spectroscopy (2)
- wide band gap (2)
- 3D printing (1)
- ACPYPE (1)
- AMBER (1)
- ANN controller (1)
- AR (1)
- Access regulation (1)
- Actuator and Sensor Systems (1)
- Adams-Moulton (1)
- Aircraft (1)
- Alkane (1)
- Antibiotics resistance (1)
- Applied sciences (1)
- Approximated Jacobian (1)
- Artificial bulk viscosity (1)
- Atmosphere flow (1)
- Automation (1)
- Automotive (1)
- Automotive Systems (1)
- B-splines (1)
- BDF (1)
- Basis set (1)
- Battery pack configurations (1)
- Bayesian optimization (1)
- Blue light (1)
- Blume–Capel model (1)
- Blume–Emery–Griffith model (1)
- Bond graph models (1)
- CAE metadata structures (1)
- CPACS (1)
- Capacity (1)
- Carbohydrate (1)
- Cell-to-cell parameter variations (1)
- Change-Prozess (1)
- Chaotic Transceiver (1)
- Citizen Journalism (1)
- Compressible (1)
- Compressible flows (1)
- Compressor modeling (1)
- Computational chemistry (1)
- Computational fluid dynamics (1)
- Computational modeling (1)
- Contingency analysis (1)
- Critical temperature (1)
- Critique (1)
- Crystallinity (1)
- Cubature (1)
- Curie–Weiss–Potts models (1)
- Current measurement (1)
- DC electric drives (1)
- DC-cascade (1)
- Differential-algebraic equations (1)
- Draw ratio (1)
- Educational methods (1)
- Efficiency (1)
- Electric Vehicles (1)
- Electric mobility (1)
- Energy Modeling (1)
- Evaluation (1)
- Evaluation als Kommunikationsanlass (1)
- Extrusionsblasformen (1)
- FM Modulation (1)
- FPGA (1)
- First-order phase transition (1)
- Flow direction (1)
- Fluid Dynamics (1)
- Flux coefficient (1)
- Force field parameters (1)
- Forecasting (1)
- Forklifts (1)
- Fourier scatterometry (1)
- GERG gas law (1)
- GROW (1)
- Galaxy: center (1)
- Gas transport simulation (1)
- Gauss–Hermite quadrature (1)
- Genetic algorithm (1)
- Geometry (1)
- Ghana (1)
- Ghanaian health sector (1)
- Glycam06 (1)
- Gordon surface (1)
- Gromacs (1)
- HEB mixer (1)
- HTS (1)
- High-performance computing (1)
- High-resolution displays (1)
- Hydraulic components (1)
- Hydrocarbon (1)
- Hydrogen (1)
- Hyperalgesia (1)
- ISM: abundances (1)
- ISM: clouds (1)
- ISM: individual objects: IRAS 16293-2422 (1)
- ISM: individual objects: Orion KL (1)
- ISM: kinematics and dynamics (1)
- Identification and control methods (1)
- Index-1 DAEs (1)
- Integrative simulation (1)
- Julia package Differential Equations (1)
- KID (1)
- Kinetic inductance detector (1)
- Kinetic theory (1)
- LSTM (1)
- Lattice Boltzmann (1)
- Lattice Boltzmann method (1)
- Lattice-Boltzmann methods (1)
- Linear viscoelasticity (1)
- Lineare Viskoelastizität (1)
- Long-distance gas network (1)
- Low temperature detectors (1)
- MKID (1)
- MP2.5 (1)
- MRT-LBM (1)
- Machine Learning (1)
- Machine learning (1)
- Machine vision (1)
- Maximal covering location problem (1)
- Media Reporting (1)
- Membrane protein (1)
- Meso-scale simulation (1)
- Metal hydride storage (1)
- Method of lines (1)
- Metrological applications (1)
- Model exchange (1)
- Modeling (1)
- Modelling (1)
- Mold temperature (1)
- Molecular dynamics (1)
- Molecular modeling (1)
- Molecular rotation (1)
- Molecular simulation (1)
- Motion Control Systems (1)
- Multi-drug efflux (1)
- Multi-objective (1)
- Multi-stage (1)
- Multiphase flow (1)
- Multiport converter (1)
- Navier-Stokes equation (1)
- Network simulation (1)
- Neural collision operator (1)
- Neuropathic pain (1)
- Non-zero external field (1)
- Nonbonded scaling factor (1)
- Numerical optimization (1)
- Numerical stability (1)
- OFDM-based DCSK (1)
- OFDM-based SR-QCSK (1)
- Object oriented modeling (1)
- Ocean flow (1)
- Off-lattice Boltzmann (1)
- On-Off Keying (1)
- Order conditions (1)
- Order reduction (1)
- Organic compounds and Functional groups (1)
- Orifices (1)
- Orthogonal chaotic vector shift keying (1)
- Orthotropic material behavior (1)
- Outer membrane channel (1)
- P3HT (1)
- PWM converters (1)
- Participatory Journalism (1)
- Peer methods (1)
- Power flow control (1)
- Power-to-gas (1)
- Process dependent material parameters (1)
- Public Opinion (1)
- Quality diversity (1)
- Qualitätspakt Lehre (1)
- Quantum mechanical methods (1)
- Range variability (1)
- Rapid Prototyping (1)
- Reanalysis (1)
- Receivers (1)
- Renewable energy (1)
- Rodas5 (1)
- Rosenbrock methods (1)
- Rosenbrock–Wanner methods (1)
- SARIMA (1)
- SOFIA (GREAT) (1)
- Sahel zone (1)
- Saint-Venant equations (1)
- Satellite (1)
- Schwindung (1)
- Second-order phase transition (1)
- Shallow-water equations (1)
- Shan-Chen model (1)
- Simulation (1)
- Simulations (1)
- Single-objective (1)
- Skin detection (1)
- Software (1)
- Solar energy (1)
- Spectroscopy (1)
- Spurious velocity (1)
- Statistical Physics (1)
- Storage modulus (1)
- Stratified flow (1)
- THz astronomy (1)
- Taylor-Green (1)
- Taylor–Green vortex (1)
- Teaching Quality Pact (1)
- Treatment (1)
- Tricritical point (1)
- Turbulence (1)
- Unified modeling language (1)
- Unstructured grid (1)
- VR (1)
- Vector modulation (1)
- Verzug (1)
- Visualization (1)
- Voltage measurement (1)
- Volterra-Wiener series (1)
- W methods (1)
- WENO schemes (1)
- WENO-schemes (1)
- WRF-Solar (1)
- advanced applications (1)
- advection-diffusion reaction equations (1)
- aerosol (1)
- airborne (1)
- amino acids (1)
- analog/digital signal processing (1)
- applications (1)
- astrochemistry (1)
- atmospheric aerosol (1)
- atomistic models (1)
- biaxial stretching (1)
- biometrics (1)
- black holes (1)
- boxing (1)
- braking (1)
- change process (1)
- chemical reactions (1)
- circumstellar matter (1)
- classical dance (1)
- complete basis set limit (1)
- complexity analysis (1)
- computer vision (1)
- cryogen-free magnets (1)
- cryogenics (1)
- data management (1)
- demi-plié (1)
- derivative-free optimization (1)
- design process (1)
- detectors (1)
- differential-algebraic equations (1)
- digital manufacturing (1)
- driver assistance system (1)
- driver interface (1)
- education (1)
- electrical bicycle drive unit (1)
- embedded systems (1)
- endoscopy (1)
- energy awareness (1)
- energy efficiency (1)
- energy infrastructures (1)
- energy system analyses (1)
- energy system modeling (1)
- engineering for non-engineers (1)
- evaluation as a mean to communication (1)
- evolution (1)
- extrusion blow molding (1)
- far-infrared astronomy (1)
- first position (1)
- flow simulation (1)
- force field parameterization (1)
- force fields (1)
- fuel (1)
- fuel cell (1)
- fully superconducting generator (1)
- gas transport networks (1)
- gas-to-power (1)
- globally convergent solvers (1)
- grating reconstruction (1)
- hand speed (1)
- heterodyne (1)
- high accuracy drives (1)
- high information rate (1)
- high resolution spectroscopy (1)
- high-temperature superconductors (1)
- hot carriers (1)
- hydrides (1)
- hydrocarbon (1)
- hydrogen (1)
- hydrogen economies (1)
- hydrogen infrastructures (1)
- impedance of battery (1)
- infrared submillimeter wave microwave (1)
- injection moulding (1)
- instrumentation: detectors (1)
- integrative Simulation (1)
- integrative simulation (1)
- interactions (1)
- interactive computer graphics (1)
- irradiance (1)
- jab (1)
- li-ion battery (1)
- lifelong learning (1)
- line: identification (1)
- line: profiles (1)
- lipid (1)
- load forecasting (1)
- long-wave infrared (1)
- low power (1)
- magnetic energy storage (1)
- magnetic hyperthermia (1)
- magnetic nanoparticles (1)
- mathematical chemistry (1)
- measurement by laser beam (1)
- medium voltage insulation (1)
- method of lines (1)
- micromobility (1)
- mixed reality (1)
- modeling (1)
- modelling (1)
- models (1)
- molecular data (1)
- molecular dynamics (1)
- molecular processes (1)
- molecular simulations (1)
- mp2 (1)
- multi-body dynamic simulation (1)
- multi-solution optimization (1)
- multidimensional Z-transforms (1)
- multistep (1)
- near infrared (1)
- neural network (1)
- neuromorphic processing (1)
- noise, vibration, and harshness (1)
- non-engineering students (1)
- nonlinear sampled-data systems (1)
- observational data and simulations (1)
- octane (1)
- ontology (1)
- optical frequency synthesizers for precision spectroscopy (1)
- optical sensor (1)
- organic compounds (1)
- orientation behavior (1)
- orthogonal frequency division multiplexing (1)
- orthotropes prozessabhängiges Materialverhalten (1)
- orthotropic process-dependent material behavior (1)
- pDPP-3T (1)
- pancreatic cancer (1)
- parameter and state estimation (1)
- patterning (1)
- peptides (1)
- performance analysis (1)
- permanent magnet synchronous generator (PMSG) (1)
- photothermal lithography (1)
- photovoltaic (1)
- planets and satellites: atmospheres (1)
- planets and satellites: detection (1)
- planets and satellites: individual: Mars (1)
- plastic manufacturing (1)
- power converter (1)
- power rectifier (1)
- power spectrum (1)
- pre-optimization (1)
- presentation attack detection (PAD) (1)
- process simulation (1)
- propan-2-ol (1)
- proteins (1)
- pulsars: individual: J1946+3417 (1)
- pulsars: individual: J2004+3429 (1)
- pulsars: individual: SGR J1745-2900 (1)
- pulse width modulation (1)
- punch (1)
- racing (1)
- radiation mechanisms: non-thermal (1)
- radiowave receivers (1)
- replica (1)
- semantic technologies (1)
- semiconducting polymers (1)
- sensor resilience (1)
- sewage systems (1)
- sewer systems (1)
- sewers (1)
- simulation (1)
- simulation process (1)
- smoothing procedures (1)
- solar power (1)
- sparse grids (1)
- spectral line broadening (1)
- spectrochemical analysis (1)
- splitting approach (1)
- stability (1)
- stars: individual: RXJ1856.5-3754 (1)
- stars: neutron (1)
- state of charge (1)
- structural dynamics (1)
- submillimeter-wave technology (1)
- submillimeter: ISM (1)
- submillimeter: general (1)
- superconducting devices (1)
- surveys (1)
- sway (1)
- synchronous generator (1)
- technological literacy (1)
- temperature control (1)
- temporal discretization (1)
- tensile test (1)
- terahertz wave spectra (1)
- therapy (1)
- thermal imaging (1)
- thermo-mechanical properties (1)
- time integration (1)
- traffic data (1)
- transmission phase gratings (1)
- trapezoidal rule (1)
- two-photon polymerization (1)
- uniaxial stretching (1)
- uninterruptible power supplies (1)
- urban planning (1)
- vehicle dynamics (1)
- velocity stabilising systems (1)
- warpage (1)
- water dimer (1)
- wind energy (1)
- wind energy conversion systems (WECS) (1)
- wind nuisance (1)
In this paper, the performance evaluation of Frequency Modulated Chaotic On-Off Keying (FM-COOK) in AWGN, Rayleigh and Rician fading channels is given. The simulation results show that an improvement in BER can be gained by incorporating the FM modulation with COOK for SNR values less than 10dB in AWGN case and less than 6dB for Rayleigh and Rician fading channels.
Trueness and precision of milled and 3D printed root-analogue implants: A comparative in vitro study
(2023)
Pipeline transport is an efficient method for transporting fluids in energy supply and other technical applications. While natural gas is the classical example, the transport of hydrogen is becoming more and more important; both are transmitted under high pressure in a gaseous state. Also relevant is the transport of carbon dioxide, captured in the places of formation, transferred under high pressure in a liquid or supercritical state and pumped into underground reservoirs for storage. The transport of other fluids is also required in technical applications. Meanwhile, the transport equations for different fluids are essentially the same, and the simulation can be performed using the same methods. In this paper, the effect of control elements such as compressors, regulators and flaptraps on the stability of fluid transport simulations is studied. It is shown that modeling of these elements can lead to instabilities, both in stationary and dynamic simulations. Special regularization methods were developed to overcome these problems. Their functionality also for dynamic simulations is demonstrated for a number of numerical experiments.
The general method of topological reduction for the network problems is presented on example of gas transport networks. The method is based on a contraction of series, parallel and tree-like subgraphs for the element equations of quadratic, power law and general monotone dependencies. The method allows to reduce significantly the complexity of the graph and to accelerate the solution procedure for stationary network problems. The method has been tested on a large set of realistic network scenarios. Possible extensions of the method have been described, including triangulated element equations, continuation of the equations at infinity, providing uniqueness of solution, a choice of Newtonian stabilizer for nearly degenerated systems. The method is applicable for various sectors in the field of energetics, including gas networks, water networks, electric networks, as well as for coupling of different sectors.
The temperature of photovoltaic modules is modelled as a dynamic function of ambient temperature, shortwave and longwave irradiance and wind speed, in order to allow for a more accurate characterisation of their efficiency. A simple dynamic thermal model is developed by extending an existing parametric steady-state model using an exponential smoothing kernel to include the effect of the heat capacity of the system. The four parameters of the model are fitted to measured data from three photovoltaic systems in the Allgäu region in Germany using non-linear optimisation. The dynamic model reduces the root-mean-square error between measured and modelled module temperature to 1.58 K on average, compared to 3.03 K for the steady-state model, whereas the maximum instantaneous error is reduced from 20.02 to 6.58 K.
Solar photovoltaic power output is modulated by atmospheric aerosols and clouds and thus contains valuable information on the optical properties of the atmosphere. As a ground-based data source with high spatiotemporal resolution it has great potential to complement other ground-based solar irradiance measurements as well as those of weather models and satellites, thus leading to an improved characterisation of global horizontal irradiance. In this work several algorithms are presented that can retrieve global tilted and horizontal irradiance and atmospheric optical properties from solar photovoltaic data and/or pyranometer measurements. The method is tested on data from two measurement campaigns that took place in the Allgäu region in Germany in autumn 2018 and summer 2019, and the results are compared with local pyranometer measurements as well as satellite and weather model data. Using power data measured at 1 Hz and averaged to 1 min resolution along with a non-linear photovoltaic module temperature model, global horizontal irradiance is extracted with a mean bias error compared to concurrent pyranometer measurements of 5.79 W m−2 (7.35 W m−2) under clear (cloudy) skies, averaged over the two campaigns, whereas for the retrieval using coarser 15 min power data with a linear temperature model the mean bias error is 5.88 and 41.87 W m−2 under clear and cloudy skies, respectively.
During completely overcast periods the cloud optical depth is extracted from photovoltaic power using a lookup table method based on a 1D radiative transfer simulation, and the results are compared to both satellite retrievals and data from the Consortium for Small-scale Modelling (COSMO) weather model. Potential applications of this approach for extracting cloud optical properties are discussed, as well as certain limitations, such as the representation of 3D radiative effects that occur under broken-cloud conditions. In principle this method could provide an unprecedented amount of ground-based data on both irradiance and optical properties of the atmosphere, as long as the required photovoltaic power data are available and properly pre-screened to remove unwanted artefacts in the signal. Possible solutions to this problem are discussed in the context of future work.
Salts and proteins comprise two of the basic molecular components of biological materials. Kosmotropic/chaotropic co-solvation and matching ion water affinities explain basic ionic effects on protein aggregation observed in simple solutions. However, it is unclear how these theories apply to proteins in complex biological environments and what the underlying ionic binding patterns are. Using the positive ion Ca2+ and the negatively charged membrane protein SNAP25, we studied ion effects on protein oligomerization in solution, in native membranes and in molecular dynamics (MD) simulations. We find that concentration-dependent ion-induced protein oligomerization is a fundamental chemico-physical principle applying not only to soluble but also to membrane-anchored proteins in their native environment. Oligomerization is driven by the interaction of Ca2+ ions with the carboxylate groups of aspartate and glutamate. From low up to middle concentrations, salt bridges between Ca2+ ions and two or more protein residues lead to increasingly larger oligomers, while at high concentrations oligomers disperse due to overcharging effects. The insights provide a conceptual framework at the interface of physics, chemistry and biology to explain binding of ions to charged protein surfaces on an atomistic scale, as occurring during protein solubilisation, aggregation and oligomerization both in simple solutions and membrane systems.
Herein we report an update to ACPYPE, a Python3 tool that now properly converts AMBER to GROMACS topologies for force fields that utilize nondefault and nonuniform 1–4 electrostatic and nonbonded scaling factors or negative dihedral force constants. Prior to this work, ACPYPE only converted AMBER topologies that used uniform, default 1–4 scaling factors and positive dihedral force constants. We demonstrate that the updated ACPYPE accurately transfers the GLYCAM06 force field from AMBER to GROMACS topology files, which employs non-uniform 1–4 scaling factors as well as negative dihedral force constants. Validation was performed using β-d-GlcNAc through gas-phase analysis of dihedral energy curves and probability density functions. The updated ACPYPE retains all of its original functionality, but now allows the simulation of complex glycomolecular systems in GROMACS using AMBER-originated force fields. ACPYPE is available for download at https://github.com/alanwilter/acpype.
Ghana suffers from frequent power outages, which can be compensated by off-grid energy solutions. Photovoltaic-hybrid systems become more and more important for rural electrification due to their potential to offer a clean and cost-effective energy supply. However, uncertainties related to the prediction of electrical loads and solar irradiance result in inefficient system control and can lead to an unstable electricity supply, which is vital for the high reliability required for applications within the health sector. Model predictive control (MPC) algorithms present a viable option to tackle those uncertainties compared to rule-based methods, but strongly rely on the quality of the forecasts. This study tests and evaluates (a) a seasonal autoregressive integrated moving average (SARIMA) algorithm, (b) an incremental linear regression (ILR) algorithm, (c) a long short-term memory (LSTM) model, and (d) a customized statistical approach for electrical load forecasting on real load data of a Ghanaian health facility, considering initially limited knowledge of load and pattern changes through the implementation of incremental learning. The correlation of the electrical load with exogenous variables was determined to map out possible enhancements within the algorithms. Results show that all algorithms show high accuracies with a median normalized root mean square error (nRMSE) <0.1 and differing robustness towards load-shifting events, gradients, and noise. While the SARIMA algorithm and the linear regression model show extreme error outliers of nRMSE >1, methods via the LSTM model and the customized statistical approaches perform better with a median nRMSE of 0.061 and stable error distribution with a maximum nRMSE of <0.255. The conclusion of this study is a favoring towards the LSTM model and the statistical approach, with regard to MPC applications within photovoltaic-hybrid system solutions in the Ghanaian health sector.
This work proposes a novel approach for probabilistic end-to-end all-sky imager-based nowcasting with horizons of up to 30 min using an ImageNet pre-trained deep neural network. The method involves a two-stage approach. First, a backbone model is trained to estimate the irradiance from all-sky imager (ASI) images. The model is then extended and retrained on image and parameter sequences for forecasting. An open access data set is used for training and evaluation. We investigated the impact of simultaneously considering global horizontal (GHI), direct normal (DNI), and diffuse horizontal irradiance (DHI) on training time and forecast performance as well as the effect of adding parameters describing the irradiance variability proposed in the literature. The backbone model estimates current GHI with an RMSE and MAE of 58.06 and 29.33 W m−2, respectively. When extended for forecasting, the model achieves an overall positive skill score reaching 18.6 % compared to a smart persistence forecast. Minor modifications to the deterministic backbone and forecasting models enables the architecture to output an asymmetrical probability distribution and reduces training time while leading to similar errors for the backbone models. Investigating the impact of variability parameters shows that they reduce training time but have no significant impact on the GHI forecasting performance for both deterministic and probabilistic forecasting while simultaneously forecasting GHI, DNI, and DHI reduces the forecast performance.
The introduction of new steering conceptsSteer-by-Wire (SBW) gives possibility to replace theconventional steering wheel by an alternative userinterface such as a sidestick. In SBW system the sidestickcan be used as user input element instead of a steeringwheel. The implementation of sidestick in the Human-Machine-Interface (HMI) allows combiningthe conventional steering consisting of a steeringwheel, an accelerator and a brake pedal into a singleelement. Also the implementation of the sidestickcreates new, interesting and flexible design optionswhich can be used to transform the driver’s spatialenvironment. This article describes an active sidestickfor a vehicle which has been developed, integrated andtested in accordance of haptic, ergonomic and safetyrelevant requirements. The control strategies used forthe active attenuators of the sidestick have beeninvestigated and optimised using a Simulink model.
Novel methods for contingency analysis of gas transport networks are presented. They are motivated by the transition of our energy system where hydrogen plays a growing role. The novel methods are based on a specific method for topological reduction and so-called supernodes. Stationary Euler equations with advanced compressor thermodynamics and a gas law allowing for gas compositions with up to 100% hydrogen are used. Several measures and plots support an intuitive comparison and analysis of the results. In particular, it is shown that the newly developed methods can estimate locations and magnitudes of additional capacities (injection, buffering, storage etc.) with a reasonable performance for networks of relevant composition and size.
Alkaline methanol oxidation is an important electrochemical process in the design of efficient fuel cells. Typically, a system of ordinary differential equations is used to model the kinetics of this process. The fitting of the parameters of the underlying mathematical model is performed on the basis of different types of experiments, characterizing the fuel cell. In this paper, we describe generic methods for creation of a mathematical model of electrochemical kinetics from a given reaction network, as well as for identification of parameters of this model. We also describe methods for model reduction, based on a combination of steady-state and dynamical descriptions of the process. The methods are tested on a range of experiments, including different concentrations of the reagents and different voltage range.
In this paper, a gas-to-power (GtoP) system for power outages is digitally modeled and experimentally developed. The design includes a solid-state hydrogen storage system composed of TiFeMn as a hydride forming alloy (6.7 kg of alloy in five tanks) and an air-cooled fuel cell (maximum power: 1.6 kW). The hydrogen storage system is charged under room temperature and 40 bar of hydrogen pressure, reaching about 110 g of hydrogen capacity. In an emergency use case of the system, hydrogen is supplied to the fuel cell, and the waste heat coming from the exhaust air of the fuel cell is used for the endothermic dehydrogenation reaction of the metal hydride. This GtoP system demonstrates fast, stable, and reliable responses, providing from 149 W to 596 W under different constant as well as dynamic conditions. A comprehensive and novel simulation approach based on a network model is also applied. The developed model is validated under static and dynamic power load scenarios, demonstrating excellent agreement with the experimental results.
Earth’s nearest candidate supermassive black hole lies at the centre of the Milky Way1. Its electromagnetic emission is thought to be powered by radiatively inefficient accretion of gas from its environment2, which is a standard mode of energy supply for most galactic nuclei. X-ray measurements have already resolved a tenuous hot gas component from which the black hole can be fed3. The magnetization of the gas, however, which is a crucial parameter determining the structure of the accretion flow, remains unknown. Strong magnetic fields can influence the dynamics of accretion, remove angular momentum from the infalling gas4, expel matter through relativistic jets5 and lead to synchrotron emission such as that previously observed6, 7, 8. Here we report multi-frequency radio measurements of a newly discovered pulsar close to the Galactic Centre9, 10, 11, 12 and show that the pulsar’s unusually large Faraday rotation (the rotation of the plane of polarization of the emission in the presence of an external magnetic field) indicates that there is a dynamically important magnetic field near the black hole. If this field is accreted down to the event horizon it provides enough magnetic flux to explain the observed emission—from radio to X-ray wavelengths—from the black hole.
Multi-epoch searches for relativistic binary pulsars and fast transients in the Galactic Centre
(2021)
We consider the Hopfield model with n neurons and an increasing number p=p(n) of randomly chosen patterns and use Stein's method to obtain rates of convergence for the central limit theorem of overlap parameters, which holds for every fixed choice of the overlap parameter for almost all realisations of the random patterns.