Refine
H-BRS Bibliography
- yes (192) (remove)
Departments, institutes and facilities
- Fachbereich Informatik (76)
- Fachbereich Angewandte Naturwissenschaften (49)
- Fachbereich Ingenieurwissenschaften und Kommunikation (37)
- Institut für Technik, Ressourcenschonung und Energieeffizienz (TREE) (35)
- Fachbereich Wirtschaftswissenschaften (23)
- Institute of Visual Computing (IVC) (18)
- Institut für funktionale Gen-Analytik (IFGA) (15)
- Graduierteninstitut (11)
- Institut für Verbraucherinformatik (IVI) (9)
- Internationales Zentrum für Nachhaltige Entwicklung (IZNE) (8)
Document Type
- Article (84)
- Conference Object (52)
- Preprint (18)
- Doctoral Thesis (11)
- Part of a Book (10)
- Research Data (4)
- Report (4)
- Book (monograph, edited volume) (3)
- Contribution to a Periodical (2)
- Master's Thesis (2)
Year of publication
- 2020 (192) (remove)
Language
- English (192) (remove)
Keywords
- Inborn error of metabolism (3)
- Organic aciduria (3)
- Quality diversity (3)
- post-buckling (3)
- ARIMA (2)
- Artificial Intelligence (2)
- Autoencoder (2)
- Automatic Short Answer Grading (2)
- Bayesian optimization (2)
- Black-Box Optimization (2)
- Computational fluid dynamics (2)
- Crystallinity (2)
- Deep Learning (2)
- Domestic Robots (2)
- Evolutionary Computation (2)
- Evolutionary computation (2)
- Ghana (2)
- Human-Centered Robotics (2)
- Hyper-parameter Tuning (2)
- Ketone body (2)
- Learning and Adaptive Systems (2)
- Metabolic acidosis (2)
- Scale Tuning (2)
- Usable Security (2)
- bank customers (2)
- computer vision (2)
- confidence level (2)
- cytokine-induced killer cells (2)
- data filtering (2)
- evolution (2)
- modeling of complex systems (2)
- neural network (2)
- nonlinear stability (2)
- object detection (2)
- robotics (2)
- short-term load forecasting (2)
- 2D Level Design (1)
- 3D (1)
- 3D interfaces (1)
- ACAT1 (1)
- ADP release (1)
- AMD Family 15h (1)
- ANN (1)
- AOP (1)
- ASIC (1)
- Abies nordmanniana (1)
- Abies procera (1)
- Acceleration (1)
- Active Learning (1)
- Activity-based probes (1)
- Aerodynamics (1)
- Africa (1)
- Ago2 (1)
- Anoplophora glabripennis (1)
- Antioxidans (1)
- Application in electrochemistry (1)
- Apprenticeship Learning (1)
- Appropriation (1)
- Ausbreitung (1)
- Authentication (1)
- Automated design (1)
- Autonomous nervous system (1)
- BERT (1)
- BPMS (1)
- Bacillus (1)
- Basis set (1)
- Bayesian Deep Learning (1)
- Beta-ketothiolase (1)
- Biaxiality (1)
- Binary and count models (1)
- BioMark HD microfluidic system (1)
- Bioactivity (1)
- Bioaktive Verbindung (1)
- Bioaktivität (1)
- Blockchain (1)
- CMOS (1)
- COVID-19 (1)
- CPUID instruction (1)
- Cache-independent (1)
- Calibration (1)
- Calorimetry (1)
- Carbon sequestration (1)
- Care (1)
- Caregiver (1)
- Cathepsin S (1)
- Chemometrics (1)
- China (1)
- Chloroquine (1)
- Classification (1)
- Co-located Collaboration (1)
- Cognition (1)
- Collaborating industrial robots (1)
- Collaboration (1)
- Complex modulus (1)
- Complex systems modeling and simulation (1)
- Compliant Manipulation (1)
- Computational Fluid Dynamics (1)
- Computer Vision (1)
- Computer-supported Cooperative Work (1)
- Connectivity in rural areas (1)
- Coumarins (1)
- Covert channel (1)
- Critical power (1)
- Cross-core (1)
- Cryptography (1)
- Cysteine proteases (1)
- DC-cascade (1)
- DNA damage (1)
- DNA profiling (1)
- Data Protection (1)
- Dementia (1)
- Demodulation pixel array (1)
- Design Case Study (1)
- Dialysis (1)
- Digital common goods (1)
- Digitisation (1)
- Disease ecology (1)
- Drahtloses lokales Netz (1)
- ELMo (1)
- ENaC (1)
- Effect of post-irradiation curing (1)
- Embedded system (1)
- Endothelin-1 (1)
- Energy meteorology (1)
- Eriodictyol (1)
- Eutectic Ti-Fe alloys (1)
- Evaluation of curing (1)
- Evolutionary optimization (1)
- Executive functions (1)
- Exergame (1)
- Extrusion blow molding (1)
- FPGA (1)
- Facial Emotion Recognition (1)
- Feature Model (1)
- Filtering (1)
- Flood resilience (1)
- Floods (1)
- Flow experience (1)
- Folk theories (1)
- Food packaging (1)
- Functional safety (1)
- Future Work (1)
- GLYCTK (1)
- GPT (1)
- GPT-2 (1)
- Galactic Cosmic Rays (GCRs) (1)
- Gaussian processes (1)
- Gebrauchstauglicher Datenschutz (1)
- Gender-based violence (1)
- Gene expression (1)
- Ghanaian banks (1)
- Green space (1)
- Group Behavior (1)
- Groupware (1)
- HEB mixer (1)
- HMGCL (1)
- Health care policy (1)
- Heart rate variability (1)
- High temperature deformation (1)
- High temperature laser powder bed fusion (1)
- High-performance computing (1)
- Hochschule Bonn-Rhein-Sieg (1)
- Human capital (1)
- Human health (1)
- Human-Robot Collaboration (1)
- Hydroxychloroquine (1)
- Hyperammonemia (1)
- Hypoglycemia (1)
- ICT (1)
- ISM: molecules (1)
- IT professionals (1)
- Image Classification (1)
- Inclusive development (1)
- Inclusive growth (1)
- Index-one DAEs (1)
- Information hiding (1)
- Inherited metabolic disorders (1)
- Instruction scheduling (1)
- Interdisciplinary research (1)
- Interferenz (1)
- Intradialytic morbid event (1)
- Isoleucine (1)
- Kenya (1)
- Ketogenesis (1)
- Ketolysis (1)
- Kunststoffverpackung (1)
- LC-HRMS (1)
- LEAP (1)
- LET (1)
- LSPR (1)
- Lamellae structure (1)
- Lattice Boltzmann Method (1)
- Learning analytics (1)
- Learning data mining (1)
- Lebensmittelverpackungen (1)
- Legal Design (1)
- Leisure thoughts (1)
- Leucine (1)
- Level-of-Detail (1)
- Lidar (1)
- Lignin (1)
- Lithium (1)
- Local process-dependent properties (1)
- Low-frequency to high-frequency (1)
- MERS (1)
- Maker space (1)
- Makers (1)
- Malus genotypes (1)
- Mars (1)
- Mars environment (1)
- Meat-associated Microorganisms (1)
- Mental models (1)
- Meso-scale simulation (1)
- Metabolic decompensation (1)
- Metabolicdecompensation (1)
- Misconception (1)
- Multi-Solution Optimization (1)
- Multi-objective optimization (1)
- Multimodal optimization (1)
- Multithreaded and multicore architecture (1)
- Mxi-2 (1)
- NIR-point sensor (1)
- Near-field synchrotron ptychographic X-ray computed tomography (1)
- Network simulation verification (1)
- Neuropilin (1)
- Next generation sequencing (NGS) (1)
- Nitriles (1)
- Non-linear optimization (1)
- OER (1)
- Object Detection (1)
- Occupational health management (1)
- Off-lattice Boltzmann (1)
- Older adults (1)
- One Health (1)
- Online identity theft (1)
- Open source software (1)
- Optical power budget (1)
- Order reduction (1)
- Orientation averaging (1)
- Out Of Distribution (OOD) data (1)
- Oxazolidinone antibiotics (1)
- PD-1/CTLA-4 (1)
- PID (1)
- PMD (1)
- Parameter identification (1)
- Passengers (1)
- Password (1)
- Pathogenic Bacteria (1)
- Peer-to-Peer (1)
- Perceived AI (1)
- Performance (1)
- Performance profiling (1)
- Phenotypic niching (1)
- Physical activity (1)
- Picea abies (1)
- Picea pungens (1)
- Portland cement (1)
- Privacy (1)
- Privacy Risk Assessment (1)
- Probabilistic model (1)
- Program effectiveness (1)
- Proof-of-Stake (1)
- Proof-of-Work (1)
- Propensity score (1)
- Prostate cancer (1)
- Protection motivation theory (1)
- Quality Diversity (1)
- Raman Spectroscopy (1)
- Re-authentication (1)
- Rehabilitation (1)
- Relative Energies (1)
- Remote Work (1)
- Rendering (1)
- Resin-based composites (1)
- Return to Work (1)
- Reversible inhibition (1)
- Risk factors (1)
- Risk-based Authentication (1)
- Risk-based Authentication (RBA) (1)
- Robo-taxi (1)
- Robot Perception (1)
- Robots (1)
- Rosenbrock-Wanner Methods (1)
- Rural women (1)
- SARS (1)
- SARS-COV-2 virus (1)
- SARS-CoV-2 (1)
- SERS (1)
- SIS mixer (1)
- Self-motion perception (1)
- Semi-Lagrangian (1)
- Serine proteases (1)
- Service Design (1)
- Sexual violence (1)
- Shared Autonomous Vehicles (1)
- Signal (1)
- Silmitasertib (1)
- Simulated sunlight (1)
- Skin cells (1)
- Skin detection (1)
- Skin flakes (1)
- Smart InGaAs camera-system (1)
- Smart image sensor (1)
- Social Protection (1)
- Socio-ecological systems (1)
- Solar power (1)
- Speed of light (1)
- Sperm cells (1)
- Spermatozoa (1)
- Splicing (1)
- Stress (1)
- Sub-Saharan Africa (1)
- Substrate mapping (1)
- Sulfonamides (1)
- Surrogate Modeling (1)
- Surrogate models (1)
- Survey (1)
- Sympathetic activation (1)
- TD-GC/MS (1)
- TOC (1)
- TOF (1)
- Task Frame Formalism (1)
- Telemedicine (1)
- Teleoperation (1)
- Thermal expansion (1)
- Time dependency (1)
- Time-of-Flight (1)
- Topological reduction (1)
- Transfer Learning (1)
- Transformation products (1)
- Trust (1)
- Two-factor Authentication (1)
- UV (1)
- UV-vis spectroscopy (1)
- Uganda (1)
- Ultimate coefficient of thermal expansion (1)
- Ultrafine microstructures (1)
- Ultrasonic array (1)
- Ultrasonic studies (1)
- Uncertainty Estimation (1)
- Uncertainty Quantification (1)
- Unfinished tasks (1)
- Unknown parameter degradation (1)
- Unstructured grid (1)
- Urban biodiversity (1)
- Urban health (1)
- Usable Privacy (1)
- User Roles (1)
- User studies (1)
- Valproic acid (1)
- Vickers hardness (1)
- Vocational re-training (1)
- W methods (1)
- WWW (1)
- Web components (1)
- Wellbeing (1)
- West Africa (1)
- Whole genome amplification (WGA) (1)
- WiFi-based Long Distance networks (1)
- Wizard of Oz (1)
- Work break (1)
- Workflow (1)
- YAWL (1)
- Young adults (1)
- Zweckbindung (1)
- accelerated iron ions (1)
- additive (1)
- advanced applications (1)
- airborne astronomy (1)
- amelogenesis (1)
- antioxidant (1)
- apple replant disease (ARD) (1)
- applications (1)
- asset transfer (1)
- astrobiology (1)
- automated sensor-screening (1)
- autonomous driving (1)
- basic human needs, evolution of behavior (1)
- bdelloid rotifer (1)
- bicausal diagnostic Bond Graphs (1)
- black fungi (1)
- blebbistatin (1)
- blockchain (1)
- brain tumor (1)
- caching (1)
- career counseling (1)
- carsharing (1)
- cementogenesis (1)
- change management (1)
- chiral-nematic (1)
- coaxial electrospinning (1)
- cognitive radio (1)
- complete basis set limit (1)
- concrete plate (1)
- conformations (1)
- coniferous woods (1)
- connected car (1)
- constraint relaxation (1)
- constraints (1)
- constructive process deviance (1)
- control architectures (1)
- convolutional neural networks (1)
- cooperative path planning (1)
- cooperative sensing (1)
- cosmic rays (1)
- cross-border trade (1)
- cryptocurrency (1)
- curved shell (1)
- cytoskeleton (1)
- d-Glycerate kinase deficiency (1)
- d-Glyceric aciduria (1)
- deep learning (1)
- dentinogenesis (1)
- dentogenesis (1)
- designing air flow (1)
- developing country (1)
- digital design (1)
- diversity (1)
- drivers (1)
- drug release materials (1)
- drugs (1)
- dynamics (1)
- e-banking transaction (1)
- e-commerce (1)
- e-learning (1)
- electroless copper deposition (1)
- empathy (1)
- encapsulation (1)
- endothelial cell differentiation (1)
- energy (1)
- energy detection (1)
- extraction (1)
- extremophile (1)
- extremophiles (1)
- failure prognostic (1)
- far-infrared astronomy (1)
- feature discovery (1)
- felt obligations (1)
- financial technology (1)
- finite element method (1)
- first-year teaching (1)
- fish gill (1)
- flow cytometry (1)
- force generation (1)
- fungi (1)
- fusion centre (1)
- gas transport networks (1)
- general plate theory (1)
- genetic neutrality (1)
- geopolymer foam (1)
- global illumination (1)
- globally convergent solvers (1)
- glycerol (1)
- graphene oxide powder (1)
- graphene oxide powders (1)
- greenhouse bio-test (1)
- growth hormone (1)
- haptics (1)
- heavy ion particle (HZE) radations (1)
- heterodyne spectroscopy (1)
- high diagnostic coverage and reliability (1)
- high dynamic range resistance readout (1)
- high-throughput qRT-PCR (1)
- hourly measurement (1)
- human behavior (1)
- iOER (1)
- immunology (1)
- immunotherapy (1)
- instance segmentation (1)
- internet banking (1)
- leisure time (1)
- life on Mars (1)
- line: identification (1)
- liquid crystal (1)
- literature review (1)
- long short-term memory (1)
- low molecular weight (1)
- lung cancer (1)
- mathematical chemistry (1)
- medium voltage insulation (1)
- melanin (1)
- melting heater (1)
- mesenchymal stem cell (1)
- mesoscopic agents (1)
- metabolic effects (1)
- microdialysis (1)
- modelling (1)
- moderator variable (1)
- molecular data (1)
- molecular dynamics simulations (1)
- molecular motor (1)
- molecular processes (1)
- monoclonal antibody (1)
- mp2 (1)
- multi-layer display (1)
- multi-objective optimization (1)
- multimodal optimization (1)
- myosin (1)
- nano-composite (1)
- natural fiber (1)
- navigation (1)
- neural networks (1)
- nutrient germinants (1)
- observational analyses (1)
- observational data and simulations (1)
- odontogenic cells (1)
- optimized geometries (1)
- orientation behavior (1)
- ozonation (1)
- ozone (1)
- p53 (1)
- panspermia (1)
- parameter estimation (1)
- payment protocol (1)
- permanent magnet synchronous generator (PMSG) (1)
- pharmacokinetics (1)
- phenotypic diversity (1)
- phenotypic feature (1)
- phenotypic niching (1)
- photolysis (1)
- phytoalexins (1)
- plastic industry (1)
- pleasant anticipation (1)
- polyethylene (1)
- porous material (1)
- power converter (1)
- predictive maintenance (1)
- process (1)
- project passed learning (1)
- propan-2-ol (1)
- psychological needs (1)
- purinergic receptor (1)
- receivers (1)
- refined beam theory (1)
- reinforcement learning (1)
- remaining useful life (1)
- remote lab (1)
- renal cancer (1)
- repeated trend projection (1)
- resistance (1)
- robot action diagnosability (1)
- robot control (1)
- robot execution failures (1)
- scaffolds (1)
- security (1)
- semantic image seg-mentation (1)
- semiconducting metal oxide gas sensor array (1)
- shell theory (1)
- small molecule (1)
- smooth muscle cell differentiation (1)
- social business (1)
- social enterprise (1)
- soil properties (1)
- sol-gel support (1)
- spectrum sensing (1)
- spore resistance (1)
- sporegermination (1)
- stabiliser (1)
- stem cells (1)
- stereoscopic vision (1)
- stiffeners (1)
- structural biology (1)
- structural coloration (1)
- subjective well-being (1)
- submillimeter-wave technology (1)
- success factors (1)
- superconducting devices (1)
- surrogate assisted phenotypic niching (1)
- surrogate models (1)
- survival (1)
- task models (1)
- technology threat avoidance theory (1)
- telepresence (1)
- temperature controller (1)
- tensile test (1)
- thermal insulation material (1)
- thermo-mechanical properties (1)
- thin film (1)
- throughput maximization (1)
- total phenolic content (1)
- trade (1)
- tunable pitch (1)
- tunable sheet resistance (1)
- ultrapure water (1)
- un-manned aerial vehicle (1)
- uncertainties (1)
- unmanned ground vehicle (1)
- usability (1)
- usable secure email (1)
- user interface design (1)
- video lectures (1)
- video methods (1)
- volatile organic compounds (1)
- water dimer (1)
- water-to-land transition (1)
- wavelet (1)
- whole-tooth regeneration (1)
- wind energy conversion systems (WECS) (1)
- wind nuisance threshold (1)
- work engagement (1)
- working alliance (1)
- Wavenet (1)
This article explores the opportunities, challenges, as well as the activities of the Chinese governmental and commercial stakeholders to promote cross-border e-commerce trade between China and Africa, based on the classification and correlation analysis of the literature from 2011 to 2019. The results show that the biggest driver for the development of China-Africa cross-border e-commerce trade is the gap between the rapid growth of the African population, especially the middle class, and the limited local capability to satisfy their demand. The rapid development of the internet and mobile internet is another driving factor. The biggest challenge is the last mile delivery of logistics, and online payment issues in Africa. At the macro-level the Chinese government has promoted measures such as infrastructure investment, e-commerce test zones and the establishment of pilot projects. At the firm level, Chinese companies have focused on solving practical micro-level local operational problems such as logistics, online payment, and talent training. The results also show that the referred literature is still in its infancy, mostly theoretical and less practical, and requires more in-depth domain specific analysis in the future.
With the digital transformation, software systems have become an integral part of our society and economy. In every part of our life, software systems are increasingly utilized to, e.g., simplify housework or to optimize business processes. All these applications are connected to the Internet, which already includes millions of software services consumed by billions of people. Applications which process such a magnitude of users and data traffic requires to be highly scalable and are therefore denoted as Ultra Large Scale (ULS) systems. Roy Fielding has defined one of the first approaches which allows designing modern ULS software systems. In his doctoral thesis, Fielding introduced the architectural style Representational State Transfer (REST) which builds the theoretical foundation of the web. At present, the web is considered as the world's largest ULS system. Due to a large number of users and the significance of software for society and the economy, the security of ULS systems is another crucial quality factor besides high scalability.
Due to the use of fossil fuel resources, many environmental problems have been increasingly growing. Thus, the recent research focuses on the use of environment friendly materials from sustainable feedstocks for future fuels, chemicals, fibers and polymers. Lignocellulosic biomass has become the raw material of choice for these new materials. Recently, the research has focused on using lignin as a substitute material in many industrial applications. The antiradical and antimicrobial activity of lignin and lignin-based films are both of great interest for applications such as food packaging additives. DPPH assay was used to determine the antioxidant activity of Kraft lignin compared to Organosolv lignins from different biomasses. The purification procedure of Kraft lignin showed that double-fold selective extraction is the most efficient confirmed by UV-Vis, FTIR, HSQC, 31PNMR, SEC, and XRD. The antioxidant capacity was discussed regarding the biomass source, pulping process, and degree of purification. Lignin obtained from industrial black liquor are compared with beech wood samples: Biomass source influences the DPPH inhibition (softwood > grass) and the TPC (softwood < grass). DPPH inhibition affected by the polarity of the extraction solvent. Following the trend: ethanol > diethylether > acetone. Reduced polydispersity has positive influence on the DPPH inhibition. Storage decreased the DPPH inhibition but increased the TPC values. The DPPH assay was also used to discuss the antiradical activity of HPMC/lignin and HPMC/lignin/chitosan films. In both binary (HPMC/lignin) and ternary (HPMC/lignin/chitosan) systems the 5% addition showed the highest activity and the highest addition had the lowest. Both scavenging activity and antimicrobial activity are dependent on the biomass source; Organosolv of softwood > Kraft of softwood > Organosolv of grass. Lignins and lignin-containing films showed high antimicrobial activities against Gram-positive and Gram-negative bacteria at 35 °C and at low temperatures (0-7 °C). Purification of Kraft lignin has a negative effect on the antimicrobial activity while storage has positive effect. The lignin leaching in the produced films affected the activity positively and the chitosan addition enhances the activity for both Gram-positive and Gram-negative bacteria. Testing the films against food spoilage bacteria that grow at low temperatures revealed the activity of the 30% addition on HPMC/L1 film against both B. thermosphacta and P. fluorescens while L5 was active only against B. thermosphacta. In HPMC/lignin/chitosan films, the 5% addition exhibited activity against both food spoilage bacteria.
Describing the elephant: a foundational model of human needs, motivation, behaviour, and wellbeing
(2020)
Models of basic psychological needs have been present and popular in the academic and lay literature for more than a century yet reviews of needs models show an astonishing lack of consensus. This raises the question of what basic human psychological needs are and if this can be consolidated into a model or framework that can align previous research and empirical study. The authors argue that the lack of consensus arises from researchers describing parts of the proverbial elephant correctly but failing to describe the full elephant. Through redefining what human needs are and matching this to an evolutionary framework we can see broad consensus across needs models and neatly slot constructs and psychological and behavioural theories into this framework. This enables a descriptive model of drives, motives, and well-being that can be simply outlined but refined enough to do justice to the complexities of human behaviour. This also raises some issues of how subjective well-being is and should be measured. Further avenues of research and how to continue building this model and framework are proposed.
Autonomous driving enables new mobility concepts such as shared-autonomous services. Although significant re-search has been done on passenger-car interaction, work on passenger interaction with robo-taxis is still rare. In this paper, we tackle the question of how passengers experience robo-taxis as a service in real-life settings to inform the interaction design. We conducted a Wizard of Oz study with an electric vehicle where the driver was hidden from the passenger to simulate the service experience of a robo-taxi. 10 participants had the opportunity to use the simulated shared-autonomous service in real-life situations for one week. By the week's end, 33 rides were completed and recorded on video. Also, we flanked the study conducting interviews before and after with all participants. The findings provided insights into four design themes that could inform the service design of robo-taxis along the different stages including hailing, pick-up, travel, and drop-off.
For a sustainable development the electricity sector needs to be decarbonized. In 2017 only 54% of the West African households had access to the electrical grid. Thus, renewable sources should play a major role for the development of the power sector in West Africa. Above all, solar power shows highest potential of renewable energy sources. However, it is highly variable, depending on the atmospheric conditions. This study addresses the challenges for a solar based power system in West Africa by analyzing the atmospheric variability of solar power. For this purpose, two aspects are investigated. In the first part, the daily power reduction due to atmospheric aerosols is quantified for different solar power technologies. Meteorological data at six ground-based stations is used to model photovoltaic and parabolic trough power during all mostly clear-sky days in 2006. A radiative transfer model is combined with solar power model. The results show, that the reduction due to aerosols can be up to 79% for photovoltaic and up to 100% for parabolic trough power plants during a major dust outbreak. Frequent dust outbreaks occurring in West Africa would cause frequent blackouts if sufficient storage capacities are not available. On average, aerosols reduce the daily power yields by 13% to 22% for photovoltaic and by 22% to 37% for parabolic troughs. For the second part, long-term atmospheric variability and trends of solar irradiance are analyzed and their impact on photovoltaic yields is examined for West Africa. Based on a 35-year satellite data record (1983 - 2017) the temporal and spatial variability and general trend are depicted for global and direct horizontal irradiances. Furthermore, photovoltaic yields are calculated on a daily basis. They show a strong meridional gradient with highest values of 5 kWh/kWp in the Sahara and Sahel zone and lowest values in southern West Africa (around 4 kWh/kWp). Thereby, the temporal variability is highest in southern West Africa (up to around 18%) and lowest in the Sahara (around 4.5%). This implies the need of a North-South grid development, to feed the increasing demand on the highly populated coast by solar power from the northern parts of West Africa. Additionally, global irradiances show a long-term positive trend (up to +5 W/m²/decade) in the Sahara and a negative trend (up to -5 W/m²/decade) in southern West Africa. If this trend is continuing, the spatial differences in solar power potential will increase in the future. This thesis provides a better understanding of the impact of atmospheric variability on solar power in a challenging environment like West Africa, characterized by the strong influence of the African monsoon. Thereby, the importance of aerosols is pointed out. Furthermore, long-term changes of irradiance are characterized concerning their implications for photovoltaic power.
Turbulent compressible flows are traditionally simulated using explicit Eulerian time integration applied to the Navier-Stokes equations. However, the associated Courant-Friedrichs-Lewy condition severely restricts the maximum time step size. Exploiting the Lagrangian nature of the Boltzmann equation's material derivative, we now introduce a feasible three-dimensional semi-Lagrangian lattice Boltzmann method (SLLBM), which elegantly circumvents this restriction. Previous lattice Boltzmann methods for compressible flows were mostly restricted to two dimensions due to the enormous number of discrete velocities needed in three dimensions. In contrast, this Rapid Communication demonstrates how cubature rules enhance the SLLBM to yield a three-dimensional velocity set with only 45 discrete velocities. Based on simulations of a compressible Taylor-Green vortex we show that the new method accurately captures shocks or shocklets as well as turbulence in 3D without utilizing additional filtering or stabilizing techniques, even when the time step sizes are up to two orders of magnitude larger compared to simulations in the literature. Our new method therefore enables researchers for the first time to study compressible turbulent flows by a fully explicit scheme, whose range of admissible time step sizes is only dictated by physics, while being decoupled from the spatial discretization.
4GREAT is an extension of the German Receiver for Astronomy at Terahertz frequencies (GREAT) operated aboard the Stratospheric Observatory for Infrared Astronomy (SOFIA). The spectrometer comprises four different detector bands and their associated subsystems for simultaneous and fully independent science operation. All detector beams are co-aligned on the sky. The frequency bands of 4GREAT cover 491-635, 890-1090, 1240-1525 and 2490-2590 GHz, respectively. This paper presents the design and characterization of the instrument, and its in-flight performance. 4GREAT saw first light in June 2018, and has been offered to the interested SOFIA communities starting with observing cycle 6.