Wissenschaftliche Artikel der BAM
Filtern
Erscheinungsjahr
- 2019 (209) (entfernen)
Dokumenttyp
- Zeitschriftenartikel (163)
- Beitrag zu einem Tagungsband (40)
- Buchkapitel (3)
- Sonstiges (2)
- Forschungsbericht (1)
Schlagworte
- Fluorescence (8)
- Nanoparticles (6)
- Ultraschall (6)
- Corrosion (5)
- Additive manufacturing (4)
- Flame retardant (4)
- Mechanochemistry (4)
- Sustainability (4)
- Zerstörungsfreie Prüfung (4)
- Additive Fertigung (3)
- Concrete (3)
- Energy label (3)
- IgG (3)
- Nanomaterial (3)
- Quantum yield (3)
- Africa (2)
- Antibody coating (2)
- Artificial neural networks (2)
- Atomic force microscopy (2)
- BODIPY (2)
- Benz[a]anthracene (BaA) (2)
- Benzo[a]pyrene (BaP) (2)
- Biochip (2)
- Bioconjugation (2)
- Biosensor (2)
- Boehmite (2)
- Carbon steel (2)
- Cellulose (2)
- Characterization (2)
- Corrosion Fatigue (2)
- DNA origami (2)
- Discotic Liquid Crystals (2)
- Distributed fiber optic sensing (2)
- Distributed vibration sensing (2)
- Dual sensing (2)
- ELISA (2)
- EPDM (2)
- ESEM (2)
- Electrochemistry (2)
- Embedded sensors (2)
- Energy transfer (2)
- Epoxy (2)
- Ettringite (2)
- Explicit dynamics (2)
- Fatigue (2)
- Fatigue tests (2)
- Fatty acid metabolism (2)
- Ferromagnetism (2)
- Friction (2)
- Gadolinium (2)
- Gas chromatography (GC) (2)
- Geruch (2)
- High Alloyed Steel (2)
- Hyperbranched (2)
- Imaging (2)
- Immunoassay (2)
- Immunocapture (2)
- Immunoglobulins (2)
- Immunoprecipitation (2)
- Immunosensor (2)
- Impact simulation (2)
- In situ (2)
- Indium phosphide (2)
- Interphase (2)
- Isogeometric analysis (2)
- Isotope dilution (ID) (2)
- Lapis lazuli (2)
- Laser beam melting (2)
- Lifetime (2)
- Lipidomic profile (2)
- Liquid chromatography (LC) (2)
- MALDI-TOF MS (2)
- Manuscripts (2)
- Mass spectrometry (MS) (2)
- Materials (2)
- Metabolic stress (2)
- Micro-XRF (2)
- NDT (2)
- Nanostructures (2)
- Normen (2)
- Optical fiber sensor (2)
- PGAA (2)
- PIXE (2)
- Phosphorus (2)
- Pigment analyses (2)
- Pitting (2)
- Polycyclic aromatic hydrocarbon (PAH) (2)
- Polylactide (2)
- Polymers (2)
- Protein A (2)
- Protein G (2)
- Provenance studies (2)
- Proximity-enhanced reaction (2)
- Quantum dots (2)
- Raman spectroscopy (2)
- Reinforced concrete (2)
- SAXS (2)
- Scattering (2)
- Sensitization (2)
- Sensor (2)
- Small-angle scattering (2)
- Standards (2)
- Structural health monitoring (2)
- Surface (2)
- Synthesis (2)
- Technical crack detection (2)
- Thermal anhydrite (2)
- ToF-SIMS (2)
- Toxicity (2)
- Tubular X-joints (2)
- Tumor metabolism (2)
- Ultrasound (2)
- Upconversion nanoparticles (2)
- VOC Emissionen (2)
- Wear (2)
- X-ray diffraction (2)
- 3D Druck (1)
- 3D inspection (1)
- 3D printing (1)
- AISI 304L (1)
- Acoustic-Structure Interaction (1)
- Additives (1)
- Adulteration (1)
- Advanced Materials (1)
- Aerial robot olfaction (1)
- Affinity chromatography (1)
- Affinitätschromatographie (1)
- Affinitätsextraktion (1)
- AgBB Bewertung (1)
- Ageing (1)
- Aggregates (1)
- Agriculture (1)
- Air conditioner (1)
- Air-conditioning (1)
- Air-coupled (1)
- Al/SiO2 composite (1)
- Alexander von Humboldt (1)
- Alkali-activated materials (1)
- Alkali-activated slag (1)
- Alpha (1)
- Altenuene (1)
- Alternaria mycotoxins (1)
- Alumina (1)
- Aluminium (1)
- Aluminum diethylphosphinate (1)
- Aluminum trihydroxide (ATH) (1)
- Amorphous carbon (1)
- Analytical methods (1)
- Analytics (1)
- Anisotropic fiber orientation (1)
- Anobium punctatum (1)
- Anomalous Small Angle X-ray Scattering (1)
- Antibacterial (1)
- Antifouling surface (1)
- Antikörper (1)
- Apis mellifera (1)
- Archaeometry (1)
- Array (1)
- Art restauration (1)
- Artificial neural network (1)
- Automated Modal Analysis for Tracking Structural Change during Construction and Operation Phases (1)
- Automated arc welding (1)
- Autophagy (1)
- BODIPYs (1)
- Bacterial adhesion (1)
- Ball milling (1)
- Bead injections (1)
- Bead-based assay (1)
- Bee diseases (1)
- Bee health (1)
- Benzin (1)
- Beton-Oberflächenschutzsysteme (1)
- Bewertung (1)
- Bias (1)
- Bildqualität (1)
- Binder (1)
- Bioactive glass (1)
- Biodegradable (1)
- Biofilm (1)
- Biological pest control (1)
- Biomarkers (1)
- Biomaterials (1)
- Biopolymer (1)
- Biosilicification (1)
- Blade (1)
- Blended cement (1)
- Bloch wall (1)
- Boden (1)
- Bodenbelag (1)
- Bodenbeläge (1)
- Boehmite nanoparticles (1)
- Borosilikatglas (1)
- Brennfleck (1)
- Brick clay (1)
- Bridge monitoring (1)
- Bridges (1)
- Broadband dielectric microscopy (1)
- Brückenmonitoring (1)
- Building materials (1)
- Bulk temperature (1)
- C-C coupling (1)
- C-OTDR (1)
- CCQM (1)
- CCUS (1)
- CFK (1)
- CO2 (1)
- CO2 separation membranes (1)
- COD-AGE (1)
- COK-12 (1)
- CONSENS (1)
- Calcined clay (1)
- Calcium phosphate (1)
- Calorimetry (1)
- Carbamazepine (1)
- Carbide (1)
- Carbon capture, utilization and storage technology (1)
- Carbon emissions (1)
- Carriers (1)
- Catalyst (1)
- Catalysts (1)
- Categorisation scheme (1)
- Cationic photocuring (1)
- Cell size (1)
- Cement admixtures (1)
- Cement clinker remnants (1)
- Cement hydration (1)
- Ceramic (1)
- Chemometrics (1)
- Chloride extraction (1)
- Chunky graphite (1)
- Civil Engineering (1)
- Civil engineering (1)
- Cleridae (1)
- Click chemistry (1)
- Clones (1)
- Co (1)
- Coating (1)
- Cobaloxime complex (1)
- Cobalt (1)
- Coda wave interferometry (1)
- Coherent optical time domain reflectometry (1)
- Cold to fast neutron testing (1)
- Coleoptera (1)
- Colourants (1)
- Compatibility evaluation (1)
- Competitive Immunoassay (1)
- Components of excitation (1)
- Composite (1)
- Composite material (1)
- Composite-Druckgefäß (1)
- Composites (1)
- Compression set (1)
- Compressive strength (1)
- Computed Tomography (1)
- Computed tomography (1)
- Condensate (1)
- Condition monitoring (1)
- Cone calorimeter (1)
- Conference (1)
- Construction (1)
- Continuous processes (1)
- Coptic (1)
- Coputed tomography (1)
- Core-shell nanoparticles (1)
- Core−shell particles (1)
- Corresponding relative humidity (1)
- Corrosion monitoring (1)
- Corrosion rate (1)
- Cr(III) complex (1)
- Crack detection (1)
- Crack formation (1)
- Crack pattern (1)
- Cracks (1)
- Cross-linking (1)
- Crosslinker (1)
- Crosslinking density (1)
- Crystalline cones (1)
- Crystallization (1)
- Cultural heritage (1)
- Curie temperature (1)
- Cybersecurity Act (1)
- Cybersicherheit (1)
- Cyclic (1)
- Cyclic load (1)
- Cyclic softening (1)
- Cyclization (1)
- Cycloaliphatic epoxy oligosiloxane (1)
- Cytotoxicity (1)
- DFA (1)
- DFG SPP 2005 (1)
- DFT (1)
- DLO (1)
- DMA (1)
- DPA (1)
- DRIFTS (1)
- DTGS (1)
- DVS (1)
- Damage detection (1)
- Dampfdruck (1)
- Damping factor (1)
- Data Fusion (1)
- Dead Sea Scrolls (1)
- Decision support (1)
- Degradation of refrigerants (1)
- Delta value (1)
- Dendritic (1)
- Density Functional Theory (1)
- Deuterium (1)
- Dibenzo[d,f][1,3,2]dioxaphosphepine 6-oxide (1)
- Dielectric breakdown (1)
- Diffraction (1)
- Digitale Radiographie (1)
- Disposal (1)
- Distributed acoustic sensing (1)
- Distributed acoustic sensing (DAS) (1)
- Distributed acoustic sensor (DAS) (1)
- Distributed fiber optic sensors (1)
- Distributed humidity sensing (1)
- Distributed sensing (1)
- Distributed strain sensing (1)
- Distributed temperature gradient sensing (1)
- Distributed vibrations sensing (DVS) (1)
- Domain wall (1)
- Double complex salts (1)
- Drone (1)
- Druckbehältern (1)
- Druckstabilität (1)
- Dual phase steel (1)
- Dye (1)
- Dynamic test method (1)
- EC definition of a nanomaterial (1)
- EC nanomaterial definition (1)
- EC/MS (1)
- EXAFS (1)
- Early oxidation (1)
- Early sulfidation (1)
- Education (1)
- Elastin (1)
- Electric impedance (1)
- Electro-fused zirconia (1)
- Electrochemical characterisation (1)
- Electrochemical impedance spectroscopy (1)
- Electromagnetic stirring (1)
- Electron microscopy (1)
- Electron transfer (1)
- Endurance Limit (1)
- Energetic Materials (1)
- Engineered Barrier System (EBS) (1)
- Epoxies (1)
- Epoxy conversion degree (1)
- Europium (1)
- Exchange interaction (1)
- Exchange length (1)
- Excimers (1)
- Expert system (1)
- FAME (1)
- FPLC (1)
- FSDC (1)
- False Positives (1)
- Faserverbund (1)
- Fe (1)
- Femtosecond laser (1)
- Fenton’s reagent (1)
- Ferritic spheroidal graphite cast iron (1)
- Ferritic steels (1)
- Ferritic–martensitic steel (1)
- Ferumoxytol (1)
- Fiber optic sensor (1)
- Fiber optic sensors (1)
- Fiber optics sensors (1)
- Fiber reinforced polymer (1)
- Fiber structuring (1)
- Fiber-optic sensing (1)
- Fiber-reinforced concrete (1)
- Fiberoptic sensors (1)
- Finite element analysis (1)
- Fire resistance (1)
- Fire test (1)
- Flame retardance (1)
- Flame retardants (1)
- Fluidic oscillator (1)
- Fluidischer Oszillator (1)
- Fluoreszenz (1)
- Fluoroacetic acid (1)
- Foams (1)
- Food (1)
- Food fermentation (1)
- Food safety (1)
- Formation (1)
- Formic Acid (1)
- Frequenzanalyse (1)
- Fs-inscription (1)
- Full Matrix Capture (1)
- Full penetration (1)
- Fully aromatic frameworks (1)
- Fungus (1)
- Funtional Groups (1)
- Galvanic corrosion (1)
- Gamma (1)
- Gas explosion (1)
- Gas sensing (1)
- Gas tomography (1)
- Gasoline (1)
- Genome (1)
- Genotoxicity testing (1)
- Geology (1)
- Geothermal (1)
- Giant magnetoresistance (1)
- Glasmonolith (1)
- Glass fiber reinforced polymers (1)
- Glass scanning (1)
- Glass-fiber-reinforced plastic transport tank (1)
- Graphene (1)
- Graphene Oxide (1)
- Ground water (1)
- Grout (1)
- Grouted connection (1)
- Guided Waves (1)
- Gypsum dehydration (1)
- HNBR (1)
- HPLC (1)
- HTS (1)
- Hapten Immunoassay (1)
- Hard metals (1)
- Hardmetal (1)
- Heat pump (1)
- Heating oil with 10 % FAME (1)
- Herbaspirillum seropedicae (1)
- Herceptin (1)
- High-fired gypsum (1)
- High-fired medieval gypsum mortars (1)
- High-voltage testing (1)
- Hot-electrons (1)
- Humboldt Codices (1)
- Hybrid laser-arc welding (1)
- Hybridoma (1)
- Hydrogel (1)
- Hydrogen (1)
- Hydrolysis (1)
- Hydrothermal fluid (1)
- Icing conditions (1)
- Illite (1)
- Imidazole (1)
- Immunglobulin (1)
- Immunoaffinity extraction (1)
- Impurities (1)
- In-situ testing (1)
- In-vivo (1)
- Inconel 718 (1)
- Incremental lifetime models (1)
- Indenter modulus (1)
- Independent test method (1)
- Infrared nano AFM (1)
- Ink (1)
- Innenraumluftqualtität (1)
- Innovation (1)
- Inspection planning (1)
- Interlaboratory comparison (1)
- Intermodulation (1)
- Intermodulation AFM (1)
- Intermodulation-AFM (1)
- Inverse analysis (1)
- Iron (1)
- Iron oxide (1)
- Isotope ratio (1)
- Isotope-labeled (1)
- Issues (1)
- Kaolinite (1)
- Kinetics (1)
- Klassifizierung (1)
- Konformitätsbewertung (1)
- Korynetes caeruleus (1)
- Künstliche Bewitterung (1)
- LC/HRMS (1)
- LL equation (1)
- LLG (1)
- Lab-on-a-Chip (1)
- Laboratory breeding (1)
- Lache (1)
- Ladder sequencing (1)
- Laminography (1)
- Landau Lifshitz Gilbert equation (1)
- Landau Lifshitz equation (1)
- Lanthanide (1)
- Large-pore (1)
- Laser Powder Bed Fusion (1)
- Laser beam welding (1)
- Laser welding (1)
- Laser-Doppler-Vibrometer (1)
- Laser-induced X-ray emission (1)
- Laser-induced nanostructures (1)
- Laser-induced periodic surface structures (LIPSS) (1)
- Laser-modified surface (1)
- Lattice structure (1)
- Layers (1)
- Leak-tightness (1)
- Lebensdauerversuche (1)
- Life history data (1)
- Lightweight materials (1)
- Local fatigue approaches (1)
- Local fatigue spproaches (1)
- Localised corrosion (1)
- Long term monitoring (1)
- Longst luminescence lifetime (1)
- Low cycle fatigue (1)
- Luftgekoppelt (1)
- Luminescence (1)
- Lysosome (1)
- MALDI (1)
- MOF (1)
- Magnesium (1)
- Magnet coupling (1)
- Magnetic (1)
- Magnetic Nanoparticles (1)
- Magnetic anisotropy (1)
- Magnetic interacion (1)
- Magnetic moment (1)
- Magnetic properties (1)
- Magnetic sensors (1)
- Magnetic thin films (1)
- Magnetization dynamics (1)
- Magnetocaloric effect (1)
- Magnéli phase (1)
- Maritime Atmosphäre (1)
- Maritime atmosphere (1)
- Market surveillance (1)
- Martensite (1)
- Maskinteknik (1)
- Mass spectrometry (1)
- Material moisture (1)
- Measurement campaigns (1)
- Mechanical Engineering (1)
- Mechanical property (1)
- Mechanical strength (1)
- Mechanistic study (1)
- Medical implants (1)
- Mehrfachreflexion (1)
- Melamine cyanurate (1)
- Melamine polyphosphate (1)
- Mesofluidics (1)
- Mesoporous Silica (1)
- Metal carbides (1)
- Metal phosphonates (1)
- Metal-Oxide Gas Sensor Array (1)
- Metal–organic frameworks (1)
- Metathesis (1)
- Method (1)
- Metrology (1)
- Microarray (1)
- Microbeads (1)
- Microcracking (1)
- Microfine Cement (1)
- Micromagnetism (1)
- Mikro-Computertomographie (1)
- Mikroplastik (1)
- Minimum energy performance standards (1)
- Mix-design (1)
- Mixed surface (1)
- Mobile robot olfaction (1)
- Modal Analysis (1)
- Model (1)
- Modified mycotoxins (1)
- Moisture (1)
- Molecular MRI (1)
- Molecular sieves (1)
- Molecule (1)
- Monensin (1)
- Monoclonal Antibodies (1)
- Mortar method (1)
- Mukuru (1)
- Multiple-layered scaffold (1)
- Multiplex (1)
- Multivariate (1)
- Multivariate data analysis (1)
- NIR (1)
- NIR Spectroscopy (1)
- NIR dyes (1)
- NMR (1)
- NMR Spectroscopy (1)
- NMR relaxometry (1)
- Nanaoparticles (1)
- Nanocasting (1)
- Nanocomposite (1)
- Nanocomposites (1)
- Nanoconfinement (1)
- Nanolenses (1)
- Nanomechanical properties (1)
- Nanomechanics (1)
- Nanoparticle dimers (1)
- Nanoporous (1)
- Nanosciences (1)
- Nanostructured material (1)
- Naphthalene (Nap) (1)
- Natural (1)
- Neel wall (1)
- Neutron Imaging (1)
- Ni (1)
- Nickel (1)
- Niobium carbide (1)
- Non-destructiv testing (1)
- Non-invasive analysis (1)
- Nosema ceranae (1)
- OOMMF (1)
- OTDR (1)
- Object oriented micromagnetic framework (1)
- Offshore foundations (1)
- Offshore wind turbines (1)
- Oligonucleotides (1)
- Optical backscatter reflectometry (1)
- Optical frequency-domain reflectometry (1)
- Optical time domain reflectometry (1)
- Organic calibration solution (1)
- Organic contaminants (1)
- Organic–inorganic nanostructures (1)
- Oriented immobilization (1)
- Origami (1)
- Oscillating magnetic field (1)
- Osmia bicornis (1)
- Oxidative metabolism (1)
- Oxygen permability (1)
- Oxygen sensitive (1)
- P92 (1)
- POD (1)
- Parabolic flight (1)
- Paramagnetism (1)
- Passive RFID (1)
- Pathogen (1)
- Pathogen transmission (1)
- Peptide library (1)
- Performance (1)
- Permeability (1)
- Pesticide (1)
- Pflanzenwachstum (1)
- Pharmaceutical (1)
- Phase transition (1)
- Phase-sensitive (1)
- Phased Array (1)
- Phospha-Michael addition (1)
- Phosphinine (1)
- Photocatalytic reduction (1)
- Photochemistry (1)
- Photon counting detector (1)
- Photophysics (1)
- Photostability (1)
- Physical relaxation (1)
- Phytoliths (1)
- Pipeline integrity (1)
- Pitting corrosion (1)
- Plant pathogen (1)
- Plasmonic heating (1)
- Plume (1)
- Polyaniline (1)
- Polycaprolactone (1)
- Polycarbonate (1)
- Polyethylene (1)
- Polyimide-coated optical fibers (1)
- Polyisocyanurate (1)
- Polymerbeschichtungen auf Beton (1)
- Polymere (1)
- Polyphosphoester (1)
- Pore fluids (1)
- Pore size distribution (1)
- Porous building materials (1)
- Porous materials (1)
- Porphyrin (1)
- Portland cement (1)
- Powder X-ray diffraction (1)
- Powder analysis (1)
- Prediction (1)
- Prevention (1)
- Probe (1)
- Properties (1)
- Ptinidae (1)
- Quality assurance (1)
- Quantitative Analysis (1)
- Quantitative moisture measurement (1)
- Quantum dot (1)
- Quellfleckgröße (1)
- RFA (1)
- RFID based sensors (1)
- Radiation protection (1)
- Rainwater (1)
- Raman (1)
- Raman band width (1)
- Raman microscopy (1)
- Raman microspectroscopy (1)
- Raman-spectroscopy (1)
- Rapid mass calorimeter (1)
- Rayleigh scattering (1)
- Re-assessment of exiting bridges (1)
- Real time measurement (1)
- Real use behavior (1)
- Real-time imaging (1)
- Real-time infrared spectroscopy (1)
- Real-time process monitoring (1)
- Real-time quality control (1)
- Refracto-vibrometry (1)
- Refraktovibrometrie (1)
- Regeneration (1)
- Regenerator (1)
- Regulatory identification of nanomaterials (1)
- Relaxation fatigue (1)
- Reliability (1)
- Repair patch (1)
- Research (1)
- Residual stress (1)
- Resistance spot welding (1)
- Restoration and conservation (1)
- Reverse glass painting (1)
- Reverse microemulsion (1)
- Rhizopus and Aspergillus oryzae (1)
- Rice (1)
- Richtcharakteristik (1)
- Risk (1)
- Risk assessment (1)
- Rissbildung in Stahl (1)
- Rosin (1)
- Roughness (1)
- Rubber (1)
- Röntgenröhre (1)
- SDC (1)
- SEM (1)
- SERS (1)
- SHM (1)
- SI Traceability (1)
- SIDA-LC-MS/MS (1)
- Safe by design (1)
- Salicylate (1)
- Salicylic acid (1)
- Salinization (1)
- Salts (1)
- Samarium doped ceria (1)
- Sandwich (1)
- Scaffolds (1)
- Scaled Boundary Finite Element Method (1)
- Scanning electrochemical microscope (SECM) (1)
- Scavenging effect of iron (1)
- Schallemission (1)
- Schallemissionsanalyse (1)
- Schallemissionsprüfung (1)
- Schichtdickenbestimmung (1)
- Schiene (1)
- Schienenprüfung (1)
- Schmiedeteile (1)
- Science (1)
- Sciences (1)
- Scission (1)
- Screed (1)
- Screening (1)
- Screening method (1)
- Seal failure (1)
- Seasonal energy efficiency ratio (1)
- Seasonal performance factor (1)
- Seismic measurement (1)
- Selective Laser Melting (1)
- Sensors (1)
- Shrinkage Reducing Admixture (1)
- Silica (1)
- Silica coating (1)
- Simulation (1)
- Single molecule (1)
- Single-source precursors (1)
- Sintering (1)
- Small angle scattering (1)
- Smart structures (1)
- Soil (1)
- Soil-structure interaction (1)
- Solid state NMR (1)
- Solid state cooling (1)
- Solitary bees (1)
- Sorghum (1)
- Spectral elements (1)
- Spectroscopic imaging (1)
- Spectroscopy (1)
- Spill evaporation (1)
- Spin (1)
- SrTiO3 (1)
- SsNMR (1)
- Stabilization (1)
- Stained glass (1)
- Standardisation (1)
- Standardisierung (1)
- Standardization (1)
- Static load (1)
- Static load monitoring (1)
- Steel (1)
- Steel structures (1)
- Stepwise growth (1)
- Stereocomplex (1)
- Stimulated Brillouin scattering (1)
- Stochastic Landau Lifshitz Gilbert equation (1)
- Stochastic Landau Lifshitz equation (1)
- Stretchable electronics (1)
- Structured light scanning (1)
- Struvite (1)
- Sub-oxide (1)
- Sulfide sensing (1)
- Superparamagnetism (1)
- Superplasticizer (1)
- Supplementary Cementitious Materials (1)
- Surface Chemistry (1)
- Surface chemistry (1)
- Surface relaxivity (1)
- Surface structures (1)
- Surface-enhanced Raman scattering (1)
- Suzuki coupling (1)
- Suzuki-Miyaura coupling (1)
- Synchrotron FTIR (1)
- Synchrotron X-ray diffraction (1)
- Synchrotron computed tomography (1)
- Synchrotron x-ray refraction radiography (SXRR) (1)
- Synergy (1)
- Synthetic Aperture Focusing Technique (1)
- T-SEM (1)
- TDLAS (1)
- TFA (1)
- THz-TDS (1)
- TW-COTDR (1)
- Tape casting (1)
- Target (1)
- Temeprature scaling (1)
- Temperature (1)
- Temperature effects (1)
- Temple Scroll (1)
- Test strips (1)
- Teststreifen (1)
- Thermal expansion (1)
- Thermoelectrics (1)
- Thermografie (1)
- Thermoplastic polyurethane (1)
- Thermoplastics (1)
- Thick materials (1)
- Thick shells (1)
- Thin film systems (1)
- Thin magnetic films (1)
- Ti-6Al-4V (1)
- Titan-Halterung (1)
- Tomographie, (1)
- Tomography of wood samples (1)
- Total Focusing Methode (1)
- Train-induced ground vibration (1)
- Transformation product (1)
- Transformation products (1)
- Trastuzumab (1)
- Tribology (1)
- Trilobite compound eyes (1)
- Triplet-triplet annihilation (1)
- Tumble dryer (1)
- UV Vis (1)
- Ultrashort laser material interaction (1)
- Ultrashort laser pulses (1)
- Upconverstion (1)
- Urban planning (1)
- Urbanisation (1)
- VIS- Spektroskopie (1)
- Validation trial (1)
- Value of action analysis (1)
- Variable frequency drive (1)
- Varroa destructor (1)
- Vehicle-track-soil interaction (1)
- Verdampfung (1)
- Verdunstung (1)
- Versalzung (1)
- Veterinary drugs (1)
- Vibration (1)
- Virulence (1)
- Vorlaufkeile (1)
- Water (1)
- Water layer thickness (1)
- Water transport (1)
- Wavenumber integrals (1)
- Wellenprüfung (1)
- Wheelset accelerations (1)
- Wild bees (1)
- Wind Turbines (1)
- Wind energy (1)
- Wind turbine (1)
- Wind turbine blades (1)
- Windgeschwindigkeit (1)
- Wirbelstrom (1)
- Wirbelstromprüfung (1)
- Wood protection (1)
- Work function (1)
- Writing materials (1)
- X-ray Photoelectron Spectroscopy (1)
- X-ray absorption Fine Spectroscopy (1)
- X-ray and electron diffraction (1)
- X-ray computed tomography (CT) (1)
- X-ray computed tomography (XCT) (1)
- X-ray reflectivity (1)
- XPS (1)
- XRD (1)
- XRF (1)
- Yb(III) complex (1)
- Yerba mate tea (1)
- Zearalenone sulfate (1)
- Zellulose (1)
- ZfP (1)
- Zuverlässigkeit (1)
- a-zearalenol (1)
- biokompatibel (1)
- gesintert (1)
- mortar method (1)
- qPCR (1)
- spectral elements (1)
- temeprature dependent exchange length (1)
- thermografisches Verfahren (1)
- µ-gravity (1)
- γ-H2AX assay (1)
Organisationseinheit der BAM
- 1 Analytische Chemie; Referenzmaterialien (51)
- 8 Zerstörungsfreie Prüfung (51)
- 6 Materialchemie (37)
- 7 Bauwerkssicherheit (35)
- 4 Material und Umwelt (18)
- 5 Werkstofftechnik (16)
- 6.3 Strukturanalytik (13)
- 8.5 Röntgenbildgebung (12)
- 9 Komponentensicherheit (12)
- 1.2 Biophotonik (11)
To increase the competitiveness of jacket substructures compared to monopiles a changeover from an individual towards a serial jacket production based on automated manufactured tubular joints combined with standardized pipes has to be achieved. Therefore, this paper addresses fatigue tests of automatically welded tubular X-joints focusing on the location of the technical fatigue crack. The detected location of the technical crack is compared to numerical investigations predicting the most fatigue prone notch considering the structural stress approach as well as the notch stress approach. Besides, the welding process of the automated manufactured tubular X-joints is presented.
Trotz moderner Sensortechnologien und Rekonstruktionsmethoden, findet die manuelle und automatisierte Ultraschallprüfung durch konventionelle Senkrecht- und Winkelprüfköpfe vielfach industriellen Einsatz.
Um einen flexiblen Prüfeinsatz und die Prüfbarkeit von einfachen sowie komplexen Geometrien zu gewährleisten, werden dort oftmals Vorlaufkeile für die Winkelprüfung mit Longitudinalwellen angewendet um eine Anzeigenschräglage und deren Reflektivität auszugleichen bzw. zu verbessern. Durch den unterschiedlichen Aufbau, im Vergleich zu integrierten Scherwellen-Winkelprüfköpfen, können jedoch während der Prüfung Fehlanzeigen generiert werden. Diese fehlerhaften Anzeigen beruhen auf Mehrfachreflexionen und Wellenumwandlungen innerhalb des Vorlaufkeils, aufgrund der Geometrie und können im Feld nur bedingt von realen Anzeigen unterschieden werden. Dieser Beitrag zeigt die geometrische Betrachtung bei der Verwendung von Vorlaufkeilen und wurde experimentell durch die Bestimmung der Richtcharakteristik und dem Einsatz von elektrodynamischen Sonden validiert. Des Weiteren ermöglichen die so gewonnenen Abhängigkeiten einen vom Keilwinkel abhängigen Verstärkungsausgleich und somit eine korrekte Größenbestimmung durch einen geeigneten Vergleichsfehler.
Cancer cell lipid class homeostasis is altered under nutrient-deprivation but stable under hypoxia
(2019)
Background: Cancer cells modify the balance between fatty acid (FA) synthesis and uptake under metabolic stress, induced by oxygen/nutrient deprivation. These modifications were shown to alter the levels of individual triglyceride (TG) or phospholipid sub-species. To attain a holistic overview of the lipidomic profiles of cancer cells under stress we performed a broad lipidomic assay, comprising 244 lipids from six major classes. This assay allowed us to perform robust analyses and assess the changes in averages of broader lipid-classes, stratified on the basis of saturation index of their fatty-acyl side chains.
Methods: Global lipidomic profiling using Liquid Chromatography-Mass Spectrometry was performed to assess lipidomic profiles of biologically diverse cancer cell lines cultivated under metabolically stressed conditions.
Results: Neutral lipid compositions were markedly modified under serum-deprived conditions and, strikingly, the cellular level of triglyceride subspecies decreased with increasing number of double bonds in their fatty acyl chains.
In contrast and unexpectedly, no robust changes were observed in lipidomic profiles of hypoxic (2% O2) Cancer cells despite concurrent changes in proliferation rates and metabolic gene expression.
Conclusions: Serum-deprivation significantly affects lipidomic profiles of cancer cells. Although, the levels of individual lipid moieties alter under hypoxia (2% O2), the robust averages of broader lipid classes remain unchanged.
The antibacterial features of natural pine/spruce rosin are well established, yet the functionality in various thermoplastics has not been surveyed. This work focuses on the processing of industrial grade purified rosin mixed with polyethylene (PE), polypropylene (PP), polylactic acid (PLA), polyamide (PA) and corn starch based biopolymer (CS). Homopolymer masterbatches were extrusion-compounded and melt-spun to form fibres for a wide range of products, such as filters, reinforcements, clothing and medical textiles. Due to the versatile chemical structure of rosin, it was observed compatible with all the selected polymers. In general, the rosin-blended systems were shear-thinning in a molten condition. The doped fibres spun of PE and PP indicated adequate melt-spinning capability and proper mechanical properties in terms of ultimate strength and Young's modulus. The antibacterial response was found dependent on the selected polymer. Especially PE with a 10 wt% rosin content showed significant antibacterial effects against Escherichia coli DH5α and Staphylococcus aureus ATCC 12598 when analysed in the Ringer's solution for 24 h.
Draft standards for the determination of organic pollutants in the solid matter of environmental matrices such as sludge, treated biowaste and soil have been basically developed in the framework of the European standardization project HORIZONTAL. A research project financed by the German Federal Environment Agency was initiated to finalize some of these CEN standard drafts, since fully validated standard procedures are crucial for the evaluation of their reliability in the context of implementation in legislation on environmental health.
Approach: Appropriate test materials (< 2mm particle size) were prepared and homogenized from contaminated soils, sludge and treated biowaste containing polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB), dioxins, furans and dioxin-like-PCB and served, along with reference solutions, as the basis for international interlaboratory comparisons. Performance data of three analytical standard procedures were obtained by the statistical evaluation of results received from 11 to 29 participants per test material.
Results: The overall variation coefficients of reproducibility (between-lab standard deviations) for the sum parameters were roughly between 10 and 35 %. The variation coefficients of repeatability (within-lab standard deviations) range between 3 % and 8 % and show no trend considering the substance groups or matrices.
The highest coefficients of reproducibility were found for the analysis of PAHs, which were between 26 and 35 %, depending on the matrix, whereas 7-17 % reproducibility was observed for toxicity equivalents (TEQ) comprising dioxins, furans and dl-PCB.
Conclusions: Overall, the results confirm that the procedures described in the Technical Specifications are fit for purpose for all three matrices and that the feasibility of the HORIZONTAL approach, to cover several matrices with one standard per analyte, was thereby proven.
Biofuels including ethanol and biodiesel (fatty acid methyl ester, FAME) represent an important renewable fuel alternative to petroleum-derived transport fuels. Increasing biofuels use would bring some benefits, such as a reduction in oil demands and greenhouse gas emissions, and an improvement in air quality. Materials compatibility is a major concern whenever the fuel composition is changed in a fuel system.
The objective of this research was to determine the resistance of frequently used sealing materials such as CR (chloroprene rubber), CSM (chlorosulfonated polyethylene), EPDM (ethylene-propylene-diene rubber), FKM (fluorocarbon rubber), FVMQ (methyl-fluorosilicone rubber), IIR (butyl rubber), NBR (acrylonitrile-butadiene rubber), PA (polyamides), PUR (polyester urethane rubber) and VMQ (methyl-vinyl-silicone rubber), in heating oil with admixtures of biogenic sources such as E10 (fuel with max. 10 % ethanol), E85 (fuel with 85 % ethanol), non-aged and aged biodiesel, diesel fuel with 5 % biodiesel, non-aged and aged B10 (heating oil with 10 % biodiesel) at 20 °C, 40 °C and 70 °C. Mass, tensile strength and breaking elongation of the test specimens were determined before and after the exposure for 84 days in the fuels. The visual examination of some elastomer test specimens clearly showed the great volume increase until break or partial dissolution. Shore hardness A and D (for PA) were determined before and after exposure of the test specimens in the biofuels for 42 days.
There is not determined a threshold for the reduction in tensile properties and Shore hardness in the international standards. Therefore, a threshold of 15 % was set for the evaluation of the compatibility. The sealing materials CR, CSM, EPDM, IIR and NBR were generally not resistant to biodiesel and B10. In summary, it can be therefore stated that the chemical resistance of the fluoropolymers FKM and FVMQ in fuels and biofuels is the best one.
The transformation of a base-catalyzed, mechano-assisted Knoevenagel condensation of mono-fluorinated benzaldehyde derivatives (p-, m-, o-benzaldehyde) with malonodinitrile was investigated in situ and in real time. Upon milling, the para-substituted product was found to crystallize initially into two different polymorphic forms, depending on the quantity of catalyst used. For low catalyst concentrations, a mechanically metastable phase (monoclinic) was initially formed, converting to the mechanically stable phase (triclinic) upon further grinding. Instead, higher catalyst concentrations crystallize directly as the triclinic product. Inclusion of catalyst in the final product, as evidenced by mass spectrometric analysis, suggests this complex polymorphic pathway may be due to seeding effects. Multivariate analysis for the in situ Raman spectra supports this complex formation pathway, and offers a new approach to monitoring multi-phase reactions during ball milling.
Localized patches are a cost- and time-effective method for repairing fiber-reinforced polymer (FRP) sandwich wind turbine rotor blade shells. To increase the understanding of their effect on the fatigue of the blades, this study examines the effect of various layup methods of localized repair patches on the structural integrity of composite sandwich structures. Manufactured with the vacuum-assisted resin infusion (VARI) process, the shell test specimens are produced as a curved structure with glass fiber reinforced polymer (GFRP) sandwiching a polyvinyl chloride (PVC) foam core. Patch repairs are then introduced with varying layup techniques, and material properties are examined with cyclic fatigue tests. The transition region between patch and parent material is studied in greater detail with finite element method (FEM) simulations, with a focus on the effect of fiber orientation mismatch. Damage onset, crack development, and eventual failure are monitored with in-situ non-destructive testing methods to develop a robust understanding of the effects of repair concepts on material stiffness and strength.
For the purpose of increasing payload and reduce freight cost, lightweight composite tank containers used for Transportation have been progressively developed during the last years. Compared to conventionally produced cylindrical steel tanks, the fiber-reinforced solutions allow greater flexibility in the tank design. Despite a number of further material-related benefits of fiber-reinforced composites as non-conductive and non-magnetic behavior as well as corrosion resistance and high strength, the optimization of their thermal degradation properties during combustion is still a challenge. To improve the fire performance of lightweight composite containers, special intumescent fire protection coatings can be applied onto the outside tank surface. This paper presents fire tests on glass-fiber-reinforced plastic transport tanks with complex geometries sheltered with different surface-applied fire protection systems. To evaluate the fire resistance of the tank structures, a fiber optic monitoring system was developed. This system is based on distributed temperature measurements using high-Resolution optical backscatter reflectometry and pointwise reference measurements using fiber Bragg gratings. Thereby, all the fiber optic sensors were directly integrated in the composite layer structure of the tanks. The focus of the presented work is on the demonstration of capability of fiber optic monitoring system in such high-temperature application. Moreover, the fiber optic measurements provide new insights into the efficiency of intumescent coating applied for fire protection of fiber-reinforced plastic transport tanks.
The objective of this study is to find out, to what extent the geochemical characteristics of lapis lazuli can be utilized in respect to its provenance. A wide range of variables is taken into consideration depending on the quantity of samples analysed from a specific geological region and the methods applied. In order to provide evidence, a multi-technique analytical approach using µXRF, ESEM, PGAA and PIXE is applied to samples from the most famous deposits of lapis lazuli. Special elements determined as fingerprints are compared in relation to the forming conditions obvious in textural features. The results and statistical output allow a differentiation that enables an optimized local classification of the blue stone. An absolute requirement for all geo-tracing performed on blue colored cultural objects of unknown provenance is awareness of the limits of analysis. The possible sources of lapis lazuli are tested by analysing the blue pigment used as paint on murals and ink on manuscripts from the Silk Road.
The initial focus of this research was on the development of a general workflow for the documentation and monitoring of historical stained glass windows using structured light scanning. Therefore windows from different churches, time periods and with different corrosion and damage phenomena were scanned before and after conservation measures. To evaluate the execution of the restoration measures the data was compared using 3D inspection software to examine the differences in geometry between the two scans. Various problems had to be solved, for example, how to deal with heavily reflective surfaces and the extreme contrast between light and dark surfaces, as seen in the borders between ‘Schwarzlot’ painting and plain glass. The application of materials for matting the surfaces, such as Cyclododecane spray, was impossible due to the high accuracy of the surface measurement required for 3D inspection. Regarding the contrast differences of the surfaces, the creation of exposure fusions and the use of polarization filters to reduce reflections were tested. In addition to the general problems encountered when recording translucent surfaces, the historical glasses caused additional problems in calculating surface comparisons. For example, the windows have to be moved and turned around several times, both during the conservation process and while scanning, causing deformations of the geometry due to the flexible lead rods allowing a certain degree of movement.
Tempeh is a common food in Indonesia, produced by fungal fermentation of soybeans using Rhizopus sp., as well as Aspergillus oryzae, for inoculation. Analogously, for economic reasons, mixtures of maize and soybeans are used for the production of so-called tempeh-like products. For maize, a contamination with the mycoestrogen zearalenone (ZEN) has been frequently reported. ZEN is a mycotoxin which is known to be metabolized by Rhizopus and Aspergillus species. Consequently, this study focused on the ZEN transformation during tempeh fermentation. Five fungal strains of the genera Rhizopus and Aspergillus, isolated from fresh Indonesian tempeh and authentic Indonesian inocula, were utilized for tempeh manufacturing from a maize/soybean mixture (30:70) at laboratory-scale. Furthermore, comparable tempeh-like products obtained from Indonesian markets were analyzed. Results from the HPLC-MS/MS analyses show that ZEN is intensely transformed into its metabolites alpha-zearalenol (alpha-ZEL), ZEN-14-sulfate, alpha-ZEL-sulfate, ZEN-14-glucoside, and ZEN-16-glucoside in tempeh production. alpha-ZEL, being significantly more toxic than ZEN, was the main metabolite in most of the Rhizopus incubations, while in Aspergillus oryzae fermentations ZEN-14-sulfate was predominantly formed. Additionally, two of the 14 authentic samples were contaminated with ZEN, alpha-ZEL and ZEN-14-sulfate, and in two further samples, ZEN and alpha-ZEL, were determined. Consequently, tempeh fermentation of ZEN-contaminated maize/soybean mixture may lead to toxification of the food item by formation of the reductive ZEN metabolite, alpha-ZEL, under model as well as authentic conditions.
Die zeitaufgelöste THz-Spektroskopie (THz-TDS) operiert mit elektromagnetischen Impulsen, die ein Amplitudenspektrum im unteren THz-Bereich aufweisen. Die THz-TDS ist in der Lage, dielektrische Volumina zerstörungs- und kontaktfreie zu durchstrahlen. Um eine 3D-THz Bildung zu ermöglichen, wurde für die THz-TDS ein rechnergestütztes Mess- und Rekonstruktionsverfahren (THz-TDSAFT) entwickelt, mit dem es gelingt, unter Verwendung der im Zeitbereich registrierten THz-TDS-Daten das Volumeninnere in Form eines dreidimensionalen Tomogramms zu rekonstruieren. Die THz-TD-SAFT basiert auf die für die Ultraschalltechnik entwickelte Synthetische Apertur Fokussierung (SAFT) bzw. des heuristisch begründeten Algorithmus des Synthetischen Apertur Radars (SAR). Anhand von Beispielen wird die Möglichkeiten der THz-TD-SAFT demonstriert und nachgewiesen, dass mit dem Rekonstruktionsansatz die künstlich eingebauten Fehlstellen bezüglich der Position und Größe geometrisch richtig im Tomogramm abgebildet werden können.
In the present study, the impact of static traffic loading on the slight deflection effects in the concrete structure of an existing bridge has been investigated using distributed fiber optic sensors. In the face of increasing traffic density and severe traffic loading, the results of the load tests on the Amsterdam bridge 705 make an important contribution to the understanding of its structural behavior. The concept of the static loading was based on the use of two 36-ton trucks stopped on the bridge at multiple pre-determined locations. The load applied in this way led to location-dependent small deflection effects recorded as longitudinal strain of the sensing fiber embedded at the underside of the bridge. The measurements were performed with a commercially-available solution based on Tunable Wavelength Coherent Optical Time Domain Reflectometry with the measurement accuracy in the range of 0.5 µm/m.
In this paper we report on the characterization by X-ray computed tomography of calcium phosphate (CaP) and polycaprolactone (PCL) coatings on Ti-6Al-4V alloy scaffolds used as a material for medical implants. The cylindrical scaffold has greater porosity of the inner part than the external part, thus, mimicking trabecular and cortical bone, respectively. The prismatic scaffolds have uniform porosity. Surface of the scaffolds was modified with calcium phosphate (CaP) and polycaprolactone (PCL) by dip-coating to improve biocompatibility and mechanical properties. Computed tomography performed with X-ray and synchrotron radiation revealed the defects of structure and morphology of CaP and PCL coatings showing small platelet-like and spider-web-like structures, respectively.
Most knowledge about the structure, function, and evolution of early compound eyes is based on investigations in trilobites. However, these studies dealt mainly with the cuticular lenses and little was known about internal anatomy. Only recently some data on crystalline cones and retinula cells were reported for a Cambrian trilobite species. Here, we describe internal eye structures of two other trilobite genera. The Ordovician Asaphus sp. reveals preserved crystalline cones situated underneath the cuticular lenses. The same is true for the Devonian species Archegonus (Waribole) warsteinensis, which in addition shows the fine structure of the rhabdom in the retinula cells. These results suggest that an apposition eye with a crystalline cone is ancestral for Trilobita. The overall similarity of trilobite eyes to those of myriapods, crustaceans, and hexapods corroborates views of a phylogenetic position of trilobites in the stem lineage of Mandibulata.
The current establishment of stretchable electronics to form a seamless link between soft or even living materials and the digital world is at the forefront of multidisciplinary research efforts, bridging physics, engineering and materials science. Magnetic functionalities can provide a sense of displacement, orientation or proximity to this novel formulation of electronics. This work reviews the recent development of stretchable magnetic field sensorics relying on the combination of metallic thin films revealing a giant magnetoresistance effect with elastomeric materials. Stretchability of the magnetic nanomembranes is achieved by specific morphologic features (e.g. wrinkles or microcracks), which accommodate the applied tensile deformation while maintaining the electrical and magnetic integrity of the sensor device. The entire development, from the demonstration of the world’s first elastically stretchable magnetic sensor to the realization of a technology platform for robust, ready-to-use elastic magnetosensorics is described. Soft giant magnetoresistive elements exhibiting the same sensing performance as on conventional rigid supports, but with fully strain invariant properties up to 270% stretching have been demonstrated. With their unique mechanical properties, these sensor elements readily conform to ubiquitous objects of arbitrary shapes including the human skin. Stretchable magnetoelectronic sensors can equip soft and epidermal electronic systems with navigation, orientation, motion tracking and touchless control capabilities. A variety of novel technologies, like electronic skins, smart textiles, soft robotics and actuators, active medical implants and soft consumer electronics will benefit from these new magnetic functionalities.
Among the various welding technologies, resistance spot welding (RSW) and laser beam welding (LBW) play a significant role as joining methods for the automobile industry. The application of RSW and LBW for the automotive body alters the microstructure in the welded areas. It is necessary to identify the mechanical properties of the welded material to be able to make a reliable statement about the material behavior and the strength of welded components. This study develops a method by which to determine the mechanical properties for the weldment of RSW and LBW for two dual phase (DP) steels, DP600 and DP1000, which are commonly used for the automotive bodies. The mechanical properties of the resistance spot weldment were obtained by performing tensile tests on the notched tensile specimen to cause an elongation of the notched and welded area in order to investigate its properties. In order to determine the mechanical properties of the laser beam weldment, indentation tests were performed on the welded material to calculate its force-penetration depth-curve. Inverse numerical simulation was used to simulate the indentation tests to determine and verify the parameters of a nonlinear isotropic material model for the weldment of LBW. Furthermore, using this method, the parameters for the material model of RSW were verified. The material parameters and microstructure of the weldment of RSW and LBW are compared and discussed. The results show that the novel method introduced in this work is a valid approach to determine the mechanical properties of welded high-strength steel structures. In addition, it can be seen that LBW and RSW lead to a reduction in ductility and an increase in the amount of yield and tensile strength of both DP600 and DP1000.
When handling flammable or toxic liquids or liquefied gases, the occurrence of a leakage and formation of a liquid pool is a scenario to be considered for risk assessment. Several models are available for the estimation of the evaporating mass flow, but only a very reduced number of experimental data is available for Validation purposes.
In the last years, the Federal Institute for Materials Research and Testing (BAM) in Berlin, Germany, carried out pool Evaporation experiments with different substances in basins with a Diameter ranging from 0,50 m to 1 m mainly on open air test sites with a built up (inner city) and a non-built-up (flat terrain) topography, but also in an enclosed space. The resulting experimental data sets cover a range of vapor pressures from 0,1 bar to 0,94 bar.
The aim of this work is to make the füll data set publicly available and to provide a description of the experimental boundary conditions.
Based on these data, a Validation of existing pool Evaporation models has been carried out and eventually led to a new formulation of an evaporation model, which is also presented here, covering the whole ränge from low wind speeds up to high vapor pressures.
The container of high-level radioactive waste (HLRW) being in deep geological disposal, the backfill material is needed to serve as the second defense for HLRW and the highly compacted bentonite is generally selected. As the time goes, the underground water will infiltrate the backfill, causing the corrosion of materials for the building of containers in the formed electrolyte. Carbon steel, titanium and its alloy are the potential candidate materials for the fabrication of HLRW containers.
The current investigation aims at assessing the safety of HLRW container in deep geological disposal for hundreds of thousands of years and facilitating the material selection for future Container fabrication by estimating their corrosion behavior in compacted bentonite with a series of moisture content at different temperatures through electrochemical methods including open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization curve (PC) measurements. The corrosion rates were estimated for a carbon steel, a pure titanium and a titanium alloy in compacted Gaomiaozi Bentonite infiltrated with simulated underground water in Beishan area of China over an expected disposal period up to 106 years respectively, showing that titanium and its alloy are more reliable materials for building HLRW containers than carbon steel.
A “turn-on” fluorescence sensing system based on a BODIPY-cobaloxime complex for the detection of H2S in liquid and gas phase was developed. To that aim, two cobaloxime complexes bearing an axial pyridyl-BODIPY ligand were initially evaluated as sensitive fluorescent HS− indicators in aqueous solution. The sensing mechanism involves the selective substitution of the BODIPY ligand by the HS− anion at the cobalt center, which is accompanied by a strong fluorescence enhancement. The selection of a complex with an ideal stability and reactivity profile toward HS− relied on the optimal interaction between the cobalt metal-center and two different pyridyl BODIPY ligands. Loading the best performing BODIPY-cobaloxime complex onto a polymeric hydrogel membrane allowed us to study the selectivity of the probe for HS− against different anions and cysteine. Successful detection of H2S by the fluorescent “light-up” membrane was not only accomplished for surface water but could also be demonstrated for relevant H2S concentrations in gas phase.
In this study, femtosecond laser-induced sub-micrometer structures are generated to modify polyethylene (PE) surface topographies. These surfaces were subjected to bacterial colonization studies with Escherichia coli and Staphylococcus aureus as test strains. The results reveal that the nanostructures do not influence S. aureus coverage, while the adhesion of E. coli is reduced.
Das vorgestellte Projekt beschäftigt sich mit den optischen, thermophysikalischen und mechanischen Materialeigenschaften von additiv gefertigten Kunststoffteilen und deren Alterung. Dazu wurden mittels Fused Layer Modeling (FLM) Probekörper aus ABS hergestellt, die anschließend für drei Monate einer künstlichen Bewitterung unterzogen wurden. Die dabei erzeugte definierte Alterung wurde nach drei Zeitabschnitten jeweils mit zerstörungsfreien Methoden charakterisiert. Dabei wurde neben den spektroskopischen Standardmethoden auch die aktive Thermografie eingesetzt. Die Ergebnisse zeigen, dass sich mittels der Thermografie sowohl chemische Veränderungen als auch mechanische Schädigungen (Fehlstellen) darstellen lassen. Die Bewitterung beeinflusst die Teiltransparenz der Proben zumindest im sichtbaren Spektralbereich, was bei der Charakterisierung der Fehlstellen, die mittels optisch angeregter aktiver Thermografie detektiert wurden, berücksichtigt werden muss.
The identification of the dynamic behavior of structures, like bridges and towers, is relevant to address multiple issues. In many cases the dynamic parameters should be acquired only once or at a frequency that doesn’t justify the installation of distinct vibration sensors for a long-term monitoring. To identify modal frequencies of a structure, a drone based mobile sensing platform has been implemented. This sensing platform measures the relative displacement be-tween the structure and the drone, which also shows a strong dynamic behavior under wind tur-bulences. By regarding the dynamic model of the drone and additional measurements at the dis-tance sensor the absolute movement of the structure can be estimated based on the measured relative distance. This time domain data is a suitable input for various operational modal analysis algorithms. The system has been used to identify the dynamic properties of test and real structure, like a 1.5 MW wind turbine tower.
NanoDefiner e-Tool: An Implemented Decision Support Framework for Nanomaterial Identification
(2019)
The European Commission’s recommendation on the definition of nanomaterial (2011/696/EU) established an applicable standard for material categorization. However, manufacturers face regulatory challenges during registration of their products. Reliable categorization is difficult and requires considerable expertise in existing measurement techniques (MTs). Additionally, organizational complexity is increased as different authorities’ registration processes require distinct reporting.
The NanoDefine project tackled these obstacles by providing the NanoDefiner e-tool: A decision support expert system for nanomaterial identification in a regulatory context. It providesMT recommendations for categorization of specific materials using a tiered approach (screening/confirmatory), and was constructed with experts from academia and industry to be extensible, interoperable, and adaptable for forthcoming revisions of the nanomaterial definition. An implemented MT-driven material categorization scheme allows detailed description. Its guided workflow is suitable for a variety of user groups. Direct feedback and explanation enable transparent decisions. Expert knowledge is Held in a knowledge base for representation of MT performance criteria and physicochemical particle type
properties. Continuous revision ensured data quality and validity. Recommendations were validated by independent case studies on industry-relevant particulate materials. Besides supporting material identification and registration, the free and open-source e-tool may serve as template for other expert systems within the nanoscience domain.
Molecular MRI is a promising in-vivo modality to detect and quantify morphological and molecular vessel-wall changes in atherosclerosis. The combination of different molecular biomarkers may improve the risk stratification of patients. This study aimed to investigate the feasibility of simultaneous visualization and quantification of plaque-burden and inflammatory activity by dual-probe molecular MRI in a mouse-model of progressive atherosclerosis and in response-to-therapy. Homozygous apolipoprotein E knockout mice (ApoE−/−) were fed a high-fat-diet (HFD) for up to four-months prior to MRI of the brachiocephalic-artery. To assess response-to-therapy, a statin was administered for the same duration. MR imaging was performed before and after administration of an elastin-specific gadolinium-based and a macrophage-specific iron-oxide-based probe. Following in-vivo MRI, samples were analyzed using histology, immunohistochemistry, inductively-coupled-mass-spectrometry and laser-inductively-coupled-mass-spectrometry. In atherosclerotic-plaques, intraplaque expression of elastic-fibers and inflammatory activity were not directly linked. While the elastin-specific probe demonstrated the highest accumulation in advanced atherosclerotic-plaques after four-months of HFD, the iron-oxide-based probe showed highest accumulation in early atherosclerotic-plaques after two-months of HFD. In-vivo measurements for the elastin and iron-oxide-probe were in good agreement with ex-vivo histopathology (Elastica-van-Giesson stain: y = 298.2 + 5.8, R2 = 0.83, p < 0.05; Perls‘ Prussian-blue-stain: y = 834.1 + 0.67, R2 = 0.88, p < 0.05). Contrast-to-noise-ratio (CNR) measurements of the elastin probe were in good agreement with ICP-MS (y = 0.11x-11.3, R² = 0.73, p < 0.05). Late stage atherosclerotic-plaques displayed the strongest increase in both CNR and gadolinium concentration (p < 0.05). The gadolinium probe did not affect the visualization of the iron-oxide-probe and vice versa. This study demonstrates the feasibility of simultaneous assessment of plaque-burden and inflammatory activity by dual-probe molecular MRI of progressive atherosclerosis. The in-vivo detection and quantification of different MR biomarkers in a single scan could be useful to improve characterization of atherosclerotic-lesions.
The moisture content of screed samples is monitored by means of embedded sensors. Relative humidity sensors and multi-ring-electrodes are used to measure the spatial moisture distribution during desorption. Based on the humidity data and the pore volume distribution, the moisture and the water layer thickness within the pore space are predicted.
Slit shape as well as cylindrical pores are evaluated. Finally, the measured real part of the electrical impedance and the calculated water layer thickness are correlated. Based on the available data, a significant trend change of the impedance is documented at a water layer thickness of approximately 3 nm. This water layer thickness corresponds to a relative humidity of 88.3%.
In civil engineering, many structures are made of reinforced concrete. Most Degradation processes relevant to this material, e.g., corrosion, are related to an increased level of material moisture.
Therefore, moisture monitoring in reinforced concrete is regarded as a crucial method for structural health monitoring. In this study, passive radio frequency identification (RFID)-based sensors are embedded into the concrete. They are well suited for long-term operation over decades and are well protected against harsh environmental conditions. The energy supply and the data transfer of the humidity sensors are provided by RFID. The sensor casing materials are optimised to withstand the high alkaline environment in concrete, having pH values of more than 12. Membrane materials are also investigated to identify materials capable of enabling water vapour transport from the porous cement matrix to the embedded humidity sensor. By measuring the corresponding relative humidity with embedded passive RFID-based sensors, the cement hydration is monitored for 170 days.
Moreover, long-term moisture monitoring is performed for more than 1000 days. The Experiments show that embedded passive RFID-based sensors are highly suitable for long-term structural health monitoring in civil engineering.
Metabolites from Alternaria fungi exhibit a variety of biological properties such as phytotoxic, cytotoxic, or antimicrobial activity. Optimization of a literature procedure culminated in an efficient total synthesis of (−)-altenuene as well as a stable isotope-labeled derivative suitable for implementation in a LC-MS/MS method for mycotoxin analysis.
In summary, we report a highly modular solid TTA-UC system comprising of a crystalline, thermally stable PCN222(Pd) MOF with CA-coated MOF channels and with a DPA annihilator embedded in a solution-like environment in the MOF channels. This solid material displays blue upconverted delayed emission with a luminescence lifetime of 373 us, a threshold value of 329 mW*cm-2 and a triplet–triplet energy transfer efficiency of 82%. This optical application adds another facet to the versatile chemistry of PCN-222 MOFs. The design concept is also applicable to other TTA-UC pairs and enables tuning of the UCL color, for example, by replacing DPA with other dyes as exemplarily shown for 2,5,8,11-tetra-tert-butyl-perylene, that yields UCL at 450 nm. Current work aims to reduce the oxygen sensitivity and to increase the retention of the trapped annihilators in organic environments, for example, by tuning the chain length of the carboxylic acid and by coating the MOF surface. In addition, the TTA-UC efficiency will be further enhanced by reducing the reabsorption of the UC emission caused by Pd(TCPP) and by optimizing the sensitizer/annihilator interface.
The hydration process of Portland cement in a cementitious system is crucial for development of the high-quality cementbased construction material. Complementary experiments of Xray diffraction analysis (XRD), scanning electron microscopy (SEM) and time-resolved laser fluorescence spectroscopy (TRLFS) using europium (Eu(III)) as an optical probe are used to analyse the hydration process of two cement systems in the absence and presence of different organic admixtures.
We Show that different analysed admixtures and the used sulphate carriers in each cement system have a significant influence on the hydration process, namely on the time-dependence in the formation of different hydrate phases of cement. Moreover, the effect of a particular admixture is related to the type of sulphate carrier used.
The quantitative information on the amounts of the crystalline cement paste components is accessible via XRD analysis. Distinctly different morphologies of ettringite and calcium-silicate-hydrates (C-S-H) determined by SEM allow visual conclusions about formation of these phases at particular ageing times. The TRLFS data provides information about the admixture influence on the course of the silicate reaction. The dip in the dependence of the luminescence decay times on the hydration time indicates the change in the structure of C-S-H in the early hydration period. Complementary information from XRD, SEM and TRLFS provides detailed information on distinct periods of the cement hydration process.
While the absorption of X-rays and gamma radiation is determined by the Z-number of the elements a specimen is composed of, it is the hydrogen making an effective contrast with neutron imaging. As a consequence, interrogating with neutrons presents a suitable tool to study the distribution of organic consolidants in materials such as wood as encountered in impregnated wooden artworks.
Four different examples of objects are presented here to demonstrate the potential of neutron CT: 1) small wooden pieces of ship wrecks (< 2 cm thickness) interrogated with cold neutrons (0.5 meV at the ANTARES facility of the FRM II in Garching) to demonstrate the potential and the limitation of using low energy neutrons, 2) a wooden statue soaked with carbolineum (fission neutrons 1.8 MeV at the NECTAR facility of the FRM II), 3) a smaller wooden figure of a skull heavily soaked with carbolineum so it was too tight for the fission neutrons used before with accelerator neutrons (broad range about 5.5 MeV at the PTB in Braunschweig) and 4) pieces of charred wood to study the impregnation with a consolidant (NECTAR, FRM II). With the exception of the last example, all results have been combined with X-ray tomography (BAM 8.3 in Berlin). In the case of the charred wood specimens (example 4) the density histograms of the neutron tomography results were compared with those obtained from untreated references. The observed gain in specific density of the soaked specimens corresponded with an increase of specific weight. All results obtained so far showed distinct distribution patterns attributable to structural peculiarities or organic consolidants providing valuable support for subsequent restoration works.
In den letzten zwei Jahren wurden 11 neue Standards/Standardrevisionen zur RT veröffentlicht (ohne Strahlenschutz) und 5 werden dafür gestrichen. Es wird über die neuen Anforderungen ausgewählter Normen bzw. Normrevisionen informiert und insbesondere auch über die veränderten Parameter, die bei Prüfpraxis und bei der Klassifizierung zu berücksichtigen sind. Das wichtigste Projekt ist die Revision der DIN EN ISO 17636-1, -2, RT von Schweißverbindungen, in ISO TC 44 SC 5 WG 1. Die Standards zur Schweißnahtprüfung in der Kerntechnik, DIN 25435, wurden ins Englische übertragen und bei ISO TC 85 SC 6 bearbeitet. Hauptaktivität bei ASTM ist gegenwärtig die Überarbeitung der CT-Standards und die Berücksichtigung der Anforderungen an das dimensionelle Messen. Der Guide ASTM E 1441 zur Bestimmung von MTF, Kontrast-Detail-Funktion (CDF) und Kontrast-Diskrimination-Diagramm (CDD) wird revidiert. E 2445 zur CR Long Term Stability wird ebenfalls revidiert. Die Revision soll auch in die ISO 16371-1 eingehen. Dazu ist ein Round Robin-Test geplant. Auch die Standards zur Durchstrahlungsprüfung auf Korrosion und Ablagerungen in Rohren mit Röntgen- und Gammastrahlen (EN 16407-1, -2, 2014) wurden revidiert. Diese Revision wurde als DIN EN ISO 20769-1, -2 2018 veröffentlicht und EN 16407 wird zurückgezogen. Die Revision der Standards EN 12543 und EN 12679 zur Messung der Brennfleckgröße und der Strahlergröße ist mit Verzögerung in Überarbeitung, um die digitalen Detektoren und Messmöglichkeiten mit Bildverarbeitungsprogrammen zu berücksichtigen. Ein Entwurf zur Messung der Brennfleckgröße von nano-Fokusröhren wird derzeit vom Europäischen Metrologie-Programm EMPIR gefördert. Zur radiographischen Gussteilprüfung wurde der Standard EN 12681 revidiert und 2018 veröffentlicht. Er wurde um Zulässigkeitsgrenzen erweitert und die digitale Radiographie wurde in Teil 2 berücksichtigt.
In this paper, we investigate the evaporation mass flow originating from spills of gas-oline. Large spills of gasoline may form during partial or complete roof sinkings or inthe case of perforations at various deck fittings at external floating roof tanks usedfor the storage. Additionally, spills may form in the retention area in the case of leak-ages at pipes or at the hull. The aim is to predict the order of magnitude of real-scaleevaporation mass flow. The determined evaporation mass flows will be used in arelated project as input values for subsequent dispersion modeling in the vicinity ofthe tanks. This is relevant for questions of fire and explosion protection as well as forenvironmental protection aspects in tank farms or refineries, which use externalfloating roof tanks. The measurements presented in this paper were compared withpredictions by empirical models and investigations of evaporations from small floorspills, round-bottom flask, or from Petri dishes published in the literature. The maingoal of this paper is to test the applicability of empirical models to provide reasonableevaporation mass flows as input for CFD dispersion simulations.
Grasses accumulate silicon in the form of silicic acid, which is precipitated as amorphous silica in microscopic particles termed phytoliths. These particles comprise a variety of morphologies according to the cell type in which the silica was deposited. Despite the evident morphological differences, phytolith chemistry has mostly been analysed in bulk samples, neglecting differences between the varied types formed in the same species. In this work, we extracted leaf phytoliths from mature plants of Sorghum bicolor (L.) Moench. Using solid state NMR and thermogravimetric analysis, we show that the extraction methods alter greatly the silica molecular structure, its condensation degree and the trapped organic matter. Measurements of individual phytoliths by Raman and synchrotron FTIR microspectroscopies in combination with multivariate analysis separated bilobate silica cells from prickles and long cells, based on the silica molecular structures and the fraction and composition of occluded organic matter. The variations in structure and composition of sorghum phytoliths suggest that the biological pathways leading to silica deposition vary between these cell types.
The fabrication and characteristics of amorphous silica reinforced Al matrix composites are studied in this paper. The major starting materials were commercial Al powder and extracted nanoparticle SiO2 (NPS) powder from Indonesian silica sands. Two different active solutions,namely N-butanol and tetramethylammonium hydroxide (TMAH), were introduced during synthesis. Characterisations in terms of physical, mechanical, microstructural and corrosion rate examinations were also employed. Introducing the SiO2 nanoparticles into the Al matrix has decreased the density and increased the porosity of the composites. The addition of N-butanol into Al/SiO2(Al/SiO2(B)) led to broader and lower X-ray diffraction profiles than the addition of TMAH (Al/SiO2(T)). From the microstructural analysis, we found that the SiO2 particles enter and agglomerate into the opening gap of the Al sheets. Furthermore, yield strength, ultimate compression strength and modulus of elasticity tended to reduce the addition of SiO2. The corrosion rate of Al/SiO2(T) was lower than that of Al/SiO2(B) composites.
Risk Assessment and Value of Action Analysis for Icing Conditions of Wind Turbines Close to Highways
(2019)
The paper presents research results from the Marie Skłodowska-Curie Innovative Training Network INFRASTAR in the field of reliability approaches for decision-making for wind turbines and bridges. This paper addresses the application of Bayesian decision analysis for installation of heating systems in wind turbine blades in cases where an ice detection system is already installed in order to allow wind turbines to be placed close to highways. Generally, application of ice detection and heating systems for wind turbines is very relevant in cases where the wind turbines are planned to be placed close to urban areas and highways, where risks need to be considered due to icing events, which may lead to consequences including human fatality, functional disruptions, and/or economic losses. The risk of people being killed in a car passing on highways near a wind turbine due to blades parts or ice pieces being thrown away in cases of overicing is considered in this paper. The probability of being killed per kilometer and per year is considered for three cases: blade parts thrown away as a result of a partial or total failure of a blade, ice thrown away in two cases, i.e., of stopped wind turbines and of wind turbines in operation. Risks due to blade parts being thrown away cannot be avoided, since low strengths of material, maintenance or manufacturing errors, mechanical or electrical failures may result in failure of a blade or blade part. The blade (parts) thrown away from wind turbines in operation imply possible consequences/fatalities for people near the wind turbines, including in areas close to highways.
Similar consequences are relevant for ice being thrown away from wind turbine blades during icing situations. In this paper, we examine the question as to whether it is valuable to put a heating System on the blades in addition to ice detection systems. This is especially interesting in countries with limited space for placing wind turbines; in addition, it is considered if higher power production can be obtained due to less downtime if a heating system is installed.
In this paper, we present and validate the concept of an autonomous aerial robot to reconstruct tomographic 2D slices of gas plumes in outdoor environments. Our platform, the so-called Unmanned Aerial Vehicle for Remote Gas Sensing (UAV-REGAS), combines a lightweight Tunable Diode Laser Absorption Spectroscopy (TDLAS) gas sensor with a 3-axis aerial stabilization gimbal for aiming at a versatile octocopter. While the TDLAS sensor provides integral gas concentration measurements, it does not measure the distance traveled by the laser diode’s beam nor the distribution of gas along the optical path. Thus, we complement the set-up with a laser rangefinder and apply principles of Computed Tomography (CT) to create a model of the spatial gas distribution from a set of integral concentration measurements. To allow for a fundamental ground truth evaluation of the applied gas tomography algorithm, we set up a unique outdoor test environment based on two 3D ultrasonic anemometers and a distributed array of 10 infrared gas transmitters. We present results showing its performance characteristics and 2D plume reconstruction capabilities under realistic conditions. The proposed system can be deployed in scenarios that cannot be addressed by currently available robots and thus constitutes a significant step forward for the field of Mobile Robot Olfaction (MRO).
Global energy consumption will increase in the future necessitating both fossil fuels and renewable energy choices - especially wind energy. Such high energy demand requires installation of offshore energy structures, rigs, platforms and towers, which are susceptible to adverse environmental conditions along with maintenances. Due to their large size and remote locations, cylindrical grouted joints are often adopted between substructure and foundation in these offshore platforms and wind structures such as monopiles. However, these connections are composite structures with exterior sleeve, interior pile and infill mortar. Degradation and settlements were reported inside similar connections, which were installed in last three decades. Besides, grouting in the offshore sites were proven difficult to obtain ideal load bearing capacity. In-situ loading conditions were also found to be affecting the failure mechanism inside such connections. This study aims at characterizing the nature of cracks generated in these grouted connections under both static and cyclic loading. Scaled grouted joints were manufactured using a novel reusable mold, and connections were loaded to failure to visualize the main failure patterns. An assessment between failure under these two types of load is drawn along with comparison to previously available literature.
Wavelength-scanning distributed acoustic sensing for structural monitoring and seismic applications
(2019)
We introduce wavelength-scanning coherent optical time domain reflectometry (WS-COTDR) for dynamic vibration sensing along optical fibers. The method is based on spectral shift computation from Rayleigh backscatter spectra. Artificial neural networks (ANNs) are used for fast and high-resolution strain computation from raw measurement data. The applicability of the method is demonstrated for vibration monitoring of a reinforced concrete bridge. We demonstrate another application example for quasi-static and dynamic measurement of ground deformation and surface wave propagation along a dark fiber in a telecommunication cable.
In September 2018, the First European Workshop on Metal Phosphonates Chemistry brought together some prominent researchers in the field of metal phosphonates and phosphinates with the aim of discussing past and current research efforts and identifying future directions. The scope of this perspective article is to provide a critical overview of the topics discussed during the workshop, which are divided into two main areas: synthesis and characterisation, and applications. In terms of synthetic methods, there has been a push towards cleaner and more efficient approaches. This has led to the introduction of high-throughput synthesis and mechanochemical synthesis. The recent success of metal–organic frameworks has also promoted renewed interest in the synthesis of porous metal phosphonates and phosphinates. Regarding characterisation, the main advances are the development of electron diffraction as a tool for crystal structure determination and the deployment of in situ characterisation techniques, which have allowed for a better understanding of reaction pathways. In terms of applications, metal phosphonates have been found to be suitable materials for several purposes: they have been employed as heterogeneous catalysts for the synthesis of fine chemicals, as solid sorbents for gas separation, notably CO2 capture, as materials for electrochemical devices, such as fuel cells and rechargeable batteries, and as matrices for drug delivery.
Modern wind turbine rotor blades consist of sandwich shell segments made from glass fiber reinforced polymers. During manufacturing, defects can arise which could lead to failure of the whole component under dynamic mechanical and thermal loads. Hence during operation defects can arise which, if detected, can be repaired locally and in-situ by applying repair patches instead of taking the whole rotor blade down and repair it remotely. This method is much more time and cost effective, since the shut-down time of the energy converter is limited to a minimum. These repair patches can, however, also lead to new defects if not applied optimally. Therefore, it is necessary to control the quality of the repair patches to ensure the best possible restoration of structural integrity of the component. As a rotor blade is an object with a large aspect ratio, X-ray laminography is predestined to provide 3D information of the objective volume. To enhance the amount of information gained from laminographic reconstruction, we use in this study a photon counting and energy discriminating X-ray detector and apply a material decomposition algorithm to the data. By inherently separating the incident spectra within the detection process into two distinct energy bins, the basis material decomposition can provide material resolved images. Choosing glass and epoxy resin as basis materials and numerically solving the inverse dual-energy equation system, the reconstructed laminographic datasets contain highly valuable information about the distribution of the basis materials within the structure. Furthermore, cross- artifacts arising from the limited angle of the projection data can be reduced by this method which allows to investigate structures that were hidden underneath the artefacts.
The aim of RILEM TC 247-DTA ‘Durability Testing of Alkali-Activated Materials’ is to identify and validate methodologies for testing the durability of alkali-activated concretes. To underpin the durability testing work of this committee, five alkali-activated concrete mixes were developed based on blast furnace slag, fly ash, and flash-calcined metakaolin. The concretes were designed with different intended performance levels, aiming to assess the capability of test methods to discriminate between concretes on this basis. A total of fifteen laboratories worldwide participated in this round robin test programme, where all concretes were produced with the same mix designs, from single-source aluminosilicate precursors and locally available aggregates. This paper reports the mix designs tested, and the compressive strength results obtained, including critical insight into reasons for the observed variability in strength within and between laboratories.
Mechanochemistry offers an environmentally benign and facile synthesis method for a variety of cement paste constituents. In addition, these methods can be used to selectively tune the properties of cement components. The mineral ettringite is an important component of cementitious materials and has additional technological potential due to its ion exchange properties.
Synthesis of ettringite via mechanochemistry is an environmentally friendly alternative to conventional wet-chemical synthesis established in industry. This contribution explores the mechanism of a two-step mechanochemical synthesis of ettringite, which was previously found to greatly improve the reaction conversion as compared with one-pot synthesis. The crystallinity of Al(OH)3 was found to decrease during the first stage of this mechanochemical synthesis. This was correlated to a significant decrease in the particle size of Al(OH)3 in this stage. No other significant changes were found for the other components, suggesting that mechanochemical activation of Al(OH)3 is responsible for the enhanced formation of ettringite by the two-step approach. The environmentally friendly approach developed for ettringite synthesis offers a versatile synthetic strategy, which can be applied to synthesise further cementitious materials.
Laser-induced periodic surface structures (LIPSS, ripples) with ~500–700 nm period were produced on titanium alloy (Ti6Al4V) surfaces upon scan processing in air by a Ti:sapphire femtosecond laser. The tribological performance of the surfaces were qualified in linear reciprocating sliding tribological tests against balls made of different materials using different oilbased lubricants. Extending our previous work, we studied the admixture of the additive 2-ethylhexyl-zinc-dithiophosphate to a base oil containing only anti-oxidants and temperature stabilizers. The presence of this additive along with the variation of the chemical composition of the counterbodies allows us to explore the synergy of the additive with the laseroxidized nanostructures.
Dual-phase membranes for high-temperature carbon dioxide Separation have emerged as promising technology to mitigate anthropogenic greenhouse gases emissions, especially as a pre- and post-combustion separation technique in coal burning power plants. To implement These membranes industrially, the carbon dioxide permeability must be improved. In this study, Ce_(0.8) Sm_(0.2) O_(2-d) (SDC) and Ce_(0.8)Sm_(0.19)Fe_(0.01)O_(2-d) (FSDC) ceramic powders were used to form the skeleton in dual-Phase membranes. The use of MgO as an environmentally friendly pore generator allows control over the membrane porosity and microstructure in order to compare the effect of the membrane’s ceramic phase. The ceramic powders and the resulting membranes were characterized using ICP-OES, HSM, gravimetric analysis, SEM/EDX, and XRD, and the carbon dioxide flux density was quantified using a high-temperature membrane permeation setup. The carbon dioxide permeability slightly increases with the addition of iron in the FSDC membranes compared to the SDC membranes mainly due to the reported scavenging effect of iron with the siliceous impurities, with an additional potential contribution of an increased crystallite size due to viscous flow sintering. The increased permeability of the FSDC system and the proper microstructure control by MgO can be further extended to optimize carbon dioxide permeability in this membrane system.
Synthesis of cyclic poly(l-lactide) catalyzed by Bismuth salicylates-A combination of two drugs
(2019)
l‐lactide was polymerized in bulk at 160 or 180°C with mixtures of bismuth subsalicylate (BiSub) and salicylic (SA) as catalysts. The SA/Bi ratio and the monomer/Bi ratio were varied. The highest molecular weights (weight average, Mw) were achieved at a SA/Bi ratio of 1/1 (Mw up to 92 000 g mol−1). l‐Lactide was also polymerized with combinations of BiSub and silylated SA, and Mw values up to 120 000 g mol−1 were achieved at 180°C. MALDI‐TOF mass spectrometry and Mark‐Houwink‐Sakurada measurements proved that under optimized reaction conditions the resulting polylactides consist of cycles.
Pipe integrity is a central concern regarding technical safety, availability, and environmental compliance of industrial plants and pipelines. A condition monitoring system that detects and localizes threats in pipes prior to occurrence of actual structural failure, e.g., leakages, especially needs to target transient events such as impacts on the pipe wall or pressure waves travelling through the medium. In the present work, it is shown that fiber-optic distributed acoustic sensing (DAS) in conjunction with a suitable application geometry of the optical fiber sensor allows to track propagating acoustic waves in the pipeline wall on a fast time-scale. Therefore, short impacts on the pipe may be localized with high fidelity. Moreover, different acoustic modes are identified, and their respective group velocities are in good agreement with theoretical predications. In another set of experiments modeling realistic damage scenarios, we demonstrate that pressure waves following explosions of different gas mixtures in pipes can be observed. Velocities are verified by local piezoelectric pressure transducers. Due to the fully distributed nature of the fiber-optic sensing system, it is possible to record accelerated motions in detail. Therefore, in addition to detection and localization of threatening events for infrastructure monitoring, DAS may provide a powerful tool to study the development of gas explosions in pipes, e.g., investigation of deflagration-to-detonation-transitions (DDT).
Investigation of the salinization in marine and offshore environment - test methods and challenges
(2019)
Salinization and contamination of metal surfaces by chloride-containing aerosols is of great importance with regard to corrosion phenomena in the maritime sector and in offshore applications. Especially Offshore Wind Turbines are exposed to extreme corrosive conditions due to high chloride concentrations in the atmosphere and the resulting high chloride deposition rates. It is of great importance to evaluate to what extent salinization of the surface influences the corrosion protection of coatings and pitting occurrence on stainless steels under atmospheric conditions to evaluate the durability of metallic building structures in offshore and marine environments. The evaluation of the scientific literature and regulatory guidelines has shown that there are still many open questions regarding the contamination of metal surfaces by chlorides. This contribution will discuss how salinization of metal surfaces is evaluated and monitored according to current standards and guidelines. Future challenges concerning test methods and the application of evaluated salinization values and deposition rates will be discussed.
The structural performance of many geotechnical systems (e.g. axially-loaded pile foundations), depends on the shearing resistance at the soil interface, which may govern the load bearing capacity of the foundation. Experimental investigations have shown that this interaction is mainly localised within a narrow shear band next to the structure. Under cyclic loading, a contraction of the soil at the interface may arise (net volume loss), possibly leading to a stress relaxation and thus to a reduction of the load bearing capacity (the so-called friction fatigue). Based on the constitutive similarities between soil continua and interfaces, we propose here the adaption of a Generalized Plasticity model for sandy soils for the numerical analysis of interface problems. In this contribution, the results of an experimental campaign for the parameter calibration of the constitutive model are presented. The tests have been conducted with a ring shear device involving different normal stresses, roughness of the steel plates as well as cyclic loading. The new modelling approach shows promising results and has the additional practical advantage that the interface zone and the soil continuum can both be described with the same constitutive model in general boundary value problems.