Filtern
Erscheinungsjahr
Dokumenttyp
- Zeitschriftenartikel (81)
- Beitrag zu einem Sammelband (23)
- Beitrag zu einem Tagungsband (23)
- Sonstiges (9)
- Forschungsbericht (2)
- Corrigendum (1)
- Preprint (1)
Sprache
- Englisch (114)
- Deutsch (24)
- Italienisch (1)
- Mehrsprachig (1)
Schlagworte
- BAMline (9)
- Synchrotron (8)
- XRF (7)
- Fungi (5)
- Color X-ray camera (4)
- Radar (4)
- SRXRF (4)
- Self-ignition (4)
- Ultrasonic echo (4)
- X-ray spectrometry (4)
- Albrecht Dürer (3)
- Explosionsschutz (3)
- Gold (3)
- NDT (3)
- RFA (3)
- Röntgenfluoreszenzanalyse (3)
- SAFT (3)
- Silberstiftzeichnung (3)
- Silverpoint drawing (3)
- Synchrotron radiation (3)
- Anlagensicherheit (2)
- Archaeometrie (2)
- Archaeometry (2)
- BESSY (2)
- Bacteria (2)
- Beton (2)
- Biomass storage (2)
- Brick (2)
- CXC (2)
- Concrete (2)
- DICONDE (2)
- Drawing (2)
- EXAFS (2)
- Free convection (2)
- Gas reaction (2)
- Gas tomography (2)
- Imaging (2)
- Laboratory test (2)
- Limestone (2)
- Luminescence (2)
- Micro-PIXE (2)
- Monoclonal antibodies (2)
- Nanoparticle (2)
- Non-destructive testing (2)
- PIM-1 (2)
- PIXE (2)
- Permeability (2)
- Plume (2)
- Polymers of intrinsic microporosity (2)
- Reactive flow (2)
- Reconstruction calculation (2)
- Sandstone (2)
- Self-heating (2)
- Sicherheitstechnik (2)
- Silber (2)
- Spannbeton (2)
- Speed of sound (2)
- TDLAS (2)
- Ultraschallecho (2)
- Umweltschutz (2)
- X-ray (2)
- ZfPBau (2)
- 3-axis gimbal (1)
- 3D-SAFT (1)
- 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide; DOPO (1)
- A Greek palimpsest (1)
- AFIT (1)
- ATR (1)
- Acoustic resonance (1)
- Acoustic resonator (1)
- Acoustic virial coefficients (1)
- Active polymer (1)
- Aerial platform (1)
- Aerial robot (1)
- Aerial robot olfaction (1)
- Aflatoxin (1)
- Ageing (1)
- Aluminoborosilicate glass (1)
- Ammonia in ambient air (1)
- Analytical services (1)
- Anisotropic wave propagation (1)
- Anti-graffiti (1)
- Anti-graffiti coatings (1)
- Antigraffiti system (1)
- Antiquity (1)
- Archäometrie (1)
- Atomic force microscopy (1)
- Aufprallecho (1)
- Authentication (1)
- Authentification (1)
- Autoignizione (self-ignition) (1)
- Automatisierung (1)
- BDS broadband dielectric spectroscopy (1)
- Back propagation (1)
- Battery (1)
- Baustoffrecycling (1)
- Bauwesen (1)
- Benchtop NMR (1)
- Binary gas mixture (1)
- Biodeterioration (1)
- Biofilm (1)
- Biofouling (1)
- Biokorrosion (1)
- Biomass quality (1)
- Biomineralization (1)
- Broadband Dielectric Spectroscopy (1)
- Built environment (1)
- Byzantine manuscript (1)
- CEC-L-103 (1)
- CLSM (1)
- CO2 + n-alkanes (1)
- Carbonate precipitation (1)
- Catalogue of services (1)
- Ceramics (1)
- Cleaning (1)
- Coal fires (1)
- Coal mineralogy (1)
- Coal petrography (1)
- Coatings (1)
- Colour (1)
- Combustibility of liquids (1)
- Communication (1)
- Compound refractive lenses (CRLs) (1)
- Computed tomography (1)
- Condition assessment (1)
- Cone calorimeter (1)
- Continuous Processes (1)
- Continuum model (1)
- Convezione naturale (free convention) (1)
- Corrosion monitoring (1)
- Covalent Organic frameworks (1)
- Cu catalysts (1)
- Cultural heritage (1)
- Cyclic load (1)
- Dacian bracelets (1)
- Data storage (1)
- Datenspeicherung (1)
- Debye-Waller parameter (1)
- Deflagration (1)
- Degradation (1)
- Depth profile (1)
- Detonation (1)
- Dibenzo[d,f][1,3,2]dioxaphosphepine 6-oxide (1)
- Dibenzo[d,f][1,3,2]dioxaphosphepine 6-oxide; BPPO (1)
- Diffusion (1)
- Diffusive Gradients in thin films (DGT) (1)
- Diffusivity (1)
- Digoxigenin (1)
- Drawings (1)
- Drehrohrofen (1)
- Dust explosions (1)
- Dynamic loads (1)
- Dynamic tests (1)
- Düngemittel (1)
- EC4SafeNano (1)
- EFIT (1)
- EFIT-modeling (1)
- ELISA (1)
- Elastic wave (1)
- Electrical properties (1)
- Electrochemical CO2 conversion (1)
- Equations of state (1)
- Erdbebensicherheit (1)
- Erhärtungsverhalten (1)
- Escherichia coli (1)
- Estradiol (1)
- Estrone (1)
- European Centre (1)
- Exothermic and pressure-inducing chemical reactions (1)
- Explosion ranges (1)
- Explosive condensed substances (1)
- Extending service life (1)
- Extrapolation methods (1)
- FACS (1)
- FT-SAFT (1)
- FX (1)
- Fehlstellen (1)
- Feuchte (1)
- Fire safety (1)
- Flame retardant (1)
- Flame retardant; (1)
- Flammable gases and vapors (1)
- Flaw characterization (1)
- Flow cytometry (1)
- Foams (1)
- Full field micro-XRF (1)
- Fundamente (1)
- Fäulnis (1)
- GC-FID (1)
- Gas permeation (1)
- Gas separation (1)
- Gaspermeation (1)
- Gilding (1)
- Gips (1)
- Glazed tiles (1)
- Gloss (1)
- Gothic incursions (1)
- Graffiti (1)
- Granite (1)
- Guided wave (1)
- HDPE (1)
- HR-TEM (1)
- Hapten (1)
- Harmful effects of substances (1)
- Heat capacity (1)
- Heat transfer (1)
- Heating (1)
- Heterogeneous explosions (1)
- Himmelsscheibe von Nebra (1)
- Historical timber structures (1)
- Historische Baustoffe (1)
- Historische Bauwerke (1)
- Holz Konstruktionen (1)
- Hot storage test (1)
- Hybrid star-shaped polymer (1)
- Hybride Gemische (1)
- Hybridoma (1)
- Hybridoma cells (1)
- Hydric properties (1)
- Hydrogen gas (1)
- Hydrogenasen (1)
- Hydrogeophysics (1)
- Ignition temperature (1)
- Immunization (1)
- Impact echo (1)
- Impact-Echo (1)
- Impact-Echo and Low Strain Techniques (1)
- Impuls Radar (1)
- Impulse response (1)
- In situ (1)
- Indische Moghulmalereien (1)
- Indoor mycobiome (1)
- Infraleichtbeton (1)
- Ingenieurbauwerke (1)
- Inline Analytics (1)
- Instrumentation for neutron sources (1)
- Integrated optical devices (1)
- Interfacial charge (1)
- Interoperability (1)
- Interoperabilität (1)
- Inverse scattering (1)
- Jan van Eyck (1)
- K-edge (1)
- Knitting (1)
- Kommunikation (1)
- Konvektion (1)
- L3-edge (1)
- Langzeitverhalten (1)
- Laser materials (1)
- Laser-induced damage (1)
- Laserscanner (1)
- Leichte Gesteinskörnungen (1)
- Leichtgranulate (1)
- Localization of gas sources (1)
- Macrophagen (1)
- Maia detector (1)
- Mauerwerkbruch (1)
- Melanins (1)
- Membrane (1)
- Metabolism (1)
- Metadata (1)
- Metal point (1)
- Metals (1)
- Micro SR-XRF (1)
- Micro-SR-XRF (1)
- Microbially Induced Corrosion (1)
- Microbiology (1)
- Minderdicken (1)
- Miscanthus x Giganteus (1)
- Miscanthus x giganteus (1)
- Mixed oxide catalyst (1)
- Mobile Robot Olfaction (1)
- Mobile robot olfaction (1)
- Model Predictive Control (1)
- Modeling (EFIT) (1)
- Modeling of wave propagation (1)
- Modellierung (1)
- Molecular identification (1)
- Monitoring (1)
- Monument (1)
- Moonmilk (1)
- NDT-CE (1)
- Nano structure (1)
- Nano-safety (1)
- Nanoalloys (1)
- Nanocomposite (1)
- Nanocomposites (1)
- Nanomaterials (1)
- Natural gas mixtures (1)
- Natural stone (1)
- Needle fibre calcite (1)
- Neutron detectors (cold, thermal, fast neutrons) (1)
- Neutron radiography (1)
- Non-destructive testing in civil engineering (1)
- Normung (1)
- Nuclear industry (1)
- Nuclear medicine (1)
- Numerical simulation (1)
- Numerical simulations (1)
- One way (1)
- Open data (1)
- Optical transfer standard (1)
- Or (1)
- Oxidation (1)
- Oxy-fuel combustion (1)
- PAA (1)
- PIGE (1)
- POSS (1)
- POSS-polycaprolactone polyurethanes (1)
- PV modules (1)
- Palladium (1)
- Perturbed-Chain Statistical Association Fluid Theory (1)
- Phase analysis (1)
- Phase evaluation (1)
- Phenotypic diversity (1)
- Phenotypic heterogeneity (1)
- Phospha-Michael addition (1)
- Phosphor (1)
- Phototrophs (1)
- PnCCD (1)
- Polycapillary optics (1)
- Polyisocyanurate (1)
- Polyisocyanurate; PIR (1)
- Polymer intrinsischer Mikroporosität (1)
- Polymers of Intrinsic Microporosity (1)
- Polypropylene (1)
- Porosity (1)
- Porous substrates (1)
- Portuguese glazed ceramics (1)
- Powders (1)
- Prestressed concrete bridges (1)
- Printers (1)
- Process Analytical Tecnology (1)
- Process optimization (1)
- Provenance (1)
- Prüfung (1)
- Pudovik reaction (1)
- Pulse echo technique (1)
- Pulsed laser deposition (1)
- Railway (1)
- Raman (1)
- Rapid prototypes (1)
- Real-time qPCR (1)
- Reazione in fase gas (gas reaction) (1)
- Recycling (1)
- Reduction factor (1)
- Reference gas standards (1)
- Reference organisms (1)
- Refractory alloys (1)
- Reinforcement (1)
- Relaxation (1)
- Renaissance (1)
- Respirometric rates (1)
- Rigid foam (1)
- Röntgenfluoreszenzanalyse (RFA) (1)
- SAFT (synthetic aperture focusing technique) (1)
- SAXS (1)
- SEM/EDX (1)
- SR-XRF analysis (1)
- SY-RFA (1)
- Scythica Vindobonensia, (1)
- Seismic investigation (1)
- Selbstentzündung (1)
- Self heating (1)
- Self ignition (1)
- Sequence annotation (1)
- Shape memory polymer (1)
- Sicherheitstechnische Kenngrößen (1)
- Silberstiftzeichnungen (1)
- Silver coins (1)
- Silverpoint (1)
- Simulation of yarn transportation (1)
- Sino-german cooperation (1)
- Slags (1)
- Small-angle X-ray scattering (1)
- Solar panels (1)
- Solid/liquid interfaces (1)
- Solubility (1)
- Spannkanäle (1)
- Speed-of-sound measurements (1)
- Spontanious ignition (1)
- Standing waves (1)
- Stiffness (1)
- Streaming current (1)
- Sub pixel analysis (1)
- Surface analysis (1)
- Surface functionalization (1)
- Surface treatments (1)
- Sy-XRF analysis (1)
- Synchrotron micro-XRF (1)
- Synthesis (1)
- Systematics (1)
- TXRF (1)
- Tangential radiography (1)
- Taxonomy (1)
- Temperature Control (1)
- Tendon ducts (1)
- Tendons (1)
- Thermo-mechanical properties (1)
- Thickness measurement (1)
- Timber (1)
- Timber pole (1)
- Timber structure (1)
- Time reversal (1)
- Tomographic reconstruction of gas plumes (1)
- Tomographie (1)
- Traceability (1)
- Transylvania (1)
- Trasporto reattivo (reactive flow) (1)
- Triple-shape polymer (1)
- Tunable Diode Laser Absorption Spectroscopy (TDLAS) (1)
- UV-VIS (1)
- UV-vis (1)
- Ultrafast phenomena (1)
- Ultraschall (1)
- Ultraschall-Echo (1)
- Ultraschallecho-Experimente an Probekörpern (1)
- Ultraschallecho-Verfahren (1)
- Ultrasonic Echo (1)
- Ultrasonic NDT (1)
- Ultrasonic echo imaging (1)
- Ultrasonics (1)
- Ultrasouind (1)
- Underground coal fires (1)
- Validation and testing infrastructure (1)
- Verpressfehler (1)
- Vienna manuscript (1)
- WAXS/SAXS (1)
- Warp knitting machine (1)
- X-Ray Fluorescence (1)
- X-ray Color Camera (1)
- X-ray absorption spectroscopy (1)
- X-ray diffraction (1)
- XANES (1)
- XRF analysis (1)
- XSW (1)
- Yarn transportation model (1)
- Zearalenone (1)
- Zeichnungen (1)
- Zerstörungsfreie Analyse (1)
- Zerstörungsfreie Prüfung im Bauwesen (1)
- ZfP (1)
- ZfP an Holzbauteilen (1)
- ZfP-Bau (1)
- compaction faults (1)
- concrete bridges (1)
- ducts (1)
- impact-echo (1)
- injection faults (1)
- magnetic stray field (1)
- pulse radar (1)
- reconstruction calculation (1)
- round robin test (1)
- ruptures in prestressing reinforcement (1)
- surface modification (1)
- synthetic aperture focusing technique (SAFT) (1)
- tendons (1)
- thermophysical properties (1)
- ultrasonic testing (1)
- upconverting nanoparticles (UCNPs) (1)
Organisationseinheit der BAM
- 6 Materialchemie (12)
- 1 Analytische Chemie; Referenzmaterialien (8)
- 6.3 Strukturanalytik (7)
- 4 Material und Umwelt (6)
- 7 Bauwerkssicherheit (6)
- 1.4 Prozessanalytik (5)
- 7.5 Technische Eigenschaften von Polymerwerkstoffen (5)
- 2 Prozess- und Anlagensicherheit (4)
- 8 Zerstörungsfreie Prüfung (4)
- 2.1 Sicherheit von Energieträgern (3)
Measurements of ion distributions at a charged solid–liquid interface using X-ray standing waves (XSW) are presented. High energy synchrotron radiation (17.48 keV) is used to produce an XSW pattern inside a thin water film on a silicon wafer. The liquid phase is an aqueous solution containing Br and Rb ions. The surface charge is adjusted by titration. Measurements are performed over a pH range from 2.2–9, using the native Si oxide layer and functional (amine) groups as surface charge. The Debye length, indicating the extension of the diffuse layer, could be measured with values varying between 1–4 nm. For functionalized wafers, the pH dependent change from attraction to repulsion of an ion species could be detected, indicating the isoelectric point. In combination with the measurement of the streaming current, the surface charge of the sample could be quantified.
We report the results of an analytical investigation
on 416 silver-copper coins stemming from the Ottoman
Empire (end of 16th and beginning of 17th centuries), using
synchrotron micro X-ray fluorescence analysis (SRXRF).
In the past, analyses had already been conducted with energy
dispersive X-ray fluorescence analysis (EDXRF), scanning
electron microscopy with energy dispersive X-ray spectrometry
(SEM/EDX) and proton induced X-ray emission spectroscopy (PIXE).With this combination of techniques it was
possible to confirm the fineness of the coinage as well as to
study the provenance of the alloy used for the coins.
For the interpretation of the data statistical analysis
(principal component analysis—PCA) has been performed.
A definite local assignment was explored and significant
clustering was obtained regarding the minor and trace elements
composing the coin alloys.
Well-defined and facetted bimetallic gold–palladium nanoalloys have been synthesized and anchored in spherical polyelectrolyte brushes (SPB) as composite particles (AuPd@SPB). These particles are better catalysts in aqueous phase than the pure metals. The atomistic arrangement of these nanoalloys has been analysed by extended X-ray absorption fine structure (EXAFS) spectroscopy at the Au–L3 and the Pd–K absorption edge. The samples with high amounts of gold appear as almost statistically mixed random alloys. Alloy compositions with less gold show slight enrichment of Pd at the surface of the particle. In addition, signals of non-metallic palladium appear at the Pd–K edge which indicate the presence of the Pd2+ species in addition to metallic palladium. The relation of these structural features to the catalytic activity is discussed.
Four hundred and sixteen silver coins stemming from the Ottoman Empire (16th and 17th centuries) were analyzed to confirm the fineness of the coinage as well as to study the provenance of the alloy used for the coins. As most of the coins showed the typical green patina on their surfaces due to corrosion processes that have led to the depletion of copper in the near surface domains of the silver coins in comparison to their core composition, small samples had to be taken, embedded in synthetic resin, and cross sectioned to investigate the true-heart metal composition. µ-synchrotron micro X-ray fluorescence analysis and µ-proton-induced X-ray emission were applied to determine the silver contents as well as the minor and trace elements. The type of the alloy was investigated as well as if coins minted in different locations demonstrated homogeneous traits concerning the predominant impurities (Au and Bi), which could suggest a common ore. Finally, energy-dispersive microanalysis in a scanning electron microscope was applied to study the homogeneity/heterogeneity of the coins and the presence of surface enrichments and to explain differences between the µ-synchrotron micro X-ray fluorescence analysis and µ-proton-induced X-ray emission measurements concerning the main component. In general, the silver content of the analyzed specimen varies between 90 and 95%. These outcomes have not supported the historical interpretations, which predict that during the period studied, a debasement of approximately 44% of the silver content of the coins should have occurred.
The conventional hybridoma screening and subcloning process is generally considered to be one of the most critical steps in hapten-specific antibody production. It is time-consuming, monoclonality is not guaranteed, and the number of clones that can be screened is limited. Our approach employs a novel hapten-specific labeling technique of hybridoma cells. This allows for fluorescence-activated cell sorting (FACS) and single-cell deposition and thereby eliminates the above-mentioned problems. A two-step staining approach is used to detect antigen specificity and antibody expression: in order to detect antigen specificity, hybridoma cells are incubated with a hapten−horseradish peroxidase conjugate (hapten−HRP), which is subsequently incubated with a fluorophore-labeled polyclonal anti-peroxidase antibody (anti-HRP−Alexa Fluor 488). To characterize the expression of membrane-bound immunoglobulin G (IgG), a fluorophore-labeled anti-mouse IgG antibody (anti-IgG−Alexa Fluor 647) is used. Hundreds of labeled hybridoma cells producing monoclonal antibodies (mAbs) specific for a hapten were rapidly isolated and deposited from a fusion mixture as single-cell clones via FACS. Enzyme-linked immunosorbent assay (ELISA) measurements of the supernatants of the sorted hybridoma clones revealed that all hapten-specific hybridoma clones secrete antibodies against the target. There are significant improvements using this high-throughput technique for the generation of mAbs including increased yield of antibody-producing hybridoma clones, ensured monoclonality of sorted cells, and reduced development times.
Surface self-assembly of spherical nanoparticles of sizes below 10 nm into hierarchical heterostructures is under arising development despite the inherent difficulties of obtaining complex ordering patterns on a larger scale. Due to template-mediated interactions between oil-dispersible superparamagnetic nanoparticles (MNPs) and polyethylenimine-stabilized gold nanoparticles (Au(PEI)NPs) at the water–oil interface of microemulsions, complex nanostructured films can be formed. Characterization of the reverse microemulsion phase by UV–vis absorption revealed the formation of heteroclusters from Winsor type II phases (WPII) using Aerosol-OT (AOT) as the surfactant. SAXS measurements verify the mechanism of initial nanoparticle clustering in defined dimensions. XPS suggested an influence of AOT at the MNP surface. Further, cryo-SEM and TEM visualization demonstrated the elongation of the reverse microemulsions into cylindrical, wormlike structures, which subsequently build up larger nanoparticle superstructure arrangements. Such WPII phases are thus proven to be a new form of soft template, mediating the self-assembly of different nanoparticles in hierarchical network-like filaments over a substrate during solvent evaporation.
The application of compact NMR instruments to hot flowing samples or exothermically reacting mixtures is limited by the temperature sensitivity of permanent magnets. Typically, such temperature effects directly influence the achievable magnetic field homogeneity and hence measurement quality. The internal-temperature control loop of the magnet and instruments is not designed for such temperature compensation. Passive insulation is restricted by the small dimensions within the magnet borehole. Here, we present a design approach for active heat shielding with the aim of variable temperature control of NMR samples for benchtop NMR instruments using a compressed airstream which is variable in flow and temperature. Based on the system identification and surface temperature measurements through thermography, a model predictive control was set up to minimise any disturbance effect on the permanent magnet from the probe or sample temperature. This methodology will facilitate the application of variable-temperature shielding and, therefore, extend the application of compact NMR instruments to flowing sample temperatures that differ from the magnet temperature.
EXAFS analysis of pure elements, binary and ternary equiatomic refractory alloys within the Nb-Zr-Ti-Hf- Ta system is performed at the Nb and Zr K-edges to analyze the evolution of the chemical local environ- ment and the lattice distortion. A good mixing of the elements is found at the atomic scale. For some compounds, a distribution of distances between the central atom and its neighbors suggests a distortion of the structure. Finally, analysis of the Debye-Waller parameters shows some correlation with the lat- tice distortion parameter δ², and allows to quantify experimentally the static disorder in medium entropy alloys.
Fire-gilding is a historic technique for the application of golden layers on a number of different base materials utilizing a gold amalgam. This technique leaves a significant amount of Hg in the golden layer, giving archeometrists a reliable indicator to identify firegildings.
Recent findings on presumably fire-gilded objects have shown in several cases significantly lower Hg content than previously studied objects. This prompted a synchrotron-based X-ray fluorescence investigation into the Hg distribution along the material–gilding interface, as well as a series of measurements regarding the Hg content development in fire-gilded samples during artificial aging. This work presents findings on laboratory-prepared fire-gildings, indicating an Hg enrichment at the interface of firegilded silver samples. Notably, such an enrichment is missing in fire-gilded copper samples. Further, it is confirmed that fire-gilded layers typically do not undercut an Hg bulk content of 5%. In this light, it seems improbable that ancient samples that contain <5% Hg are fire-gilded. The results presented in this study might lead to a non-destructive method to identify the Hg enrichment at the interface. This might be obtained by a combination of different non-destructive measurements and might also work unambiguously in samples in which the gold top layer is altered.
The impact of phosphorus-containing flame retardants (FR) on rigid polyisocyanurate (PIR) foams is studied by systematic variation of the chemical structure of the FR, including non-NCO-reactive and NCO-reactive dibenzo[d,f][1,3,2]dioxaphosphepine 6-oxide (BPPO)- and 9,10 dihydro-9-oxa-10 phosphaphenanthrene-10-oxide (DOPO)-containing compounds, among them a number of compounds not reported so far. These PIR foams are compared with PIR foams without FR and with standard FRs with respect to foam properties, thermal decomposition, and fire behavior. Although BPPO and DOPO differ by just one oxygen atom, the impact on the FR properties is very significant: when the FR is a filler or a dangling (dead) end in the PIR polymer network, DOPO is more effective than BPPO. When the FR is a subunit of a diol and it is fully incorporated in the PIR network, BPPO delivers superior results.
Polymers of intrinsic microporosity (PIMs) are promising candidates for the active layer in gas separation membranes due to their high permeability and reasonable permselectivity. These appealing properties originate from a microporous structure as a result of inefficient segment packing in the condensed state due to a combination of a ladder-like rigid backbone and sites of contortion. However, this class of polymers suffers from a significant decrease in the permeability with time due to physical aging, whereby typically, the permselectivity increases. The initial microporous structures approach a denser state via local rearrangements, leading to the reduction of the permeability. Hence, a detailed characterization of the molecular mobility in such materials can provide valuable information on physical aging. In this work, the dielectric behavior of PIM-1 films and their behavior upon heating (aging) were revisited by isothermal frequency scans during different heating/cooling cycles over a broad temperature range between 133 and 523 K (−140 to 250 °C). In addition, the obtained results were compared with data of samples that were annealed at ambient temperatures over different time scales. Multiple dielectric processes were observed: several relaxation processes due to local fluctuations and a Maxwell−Wagner−Sillars polarization effect related to the microporosity. The temperature dependence of the rates of all processes follows the Arrhenius law where the estimated activation energy depends on the nature of the process. The influence of the thermal history (aging) on the processes is discussed in detail.
Im deutschen Eisenbahnnetz sind ca. 80 Millionen Spannbetonschwellen verbaut. Analog zu anderen Bauwerken werden Wpannbetonschwellen regelmäßig visuell inspiziert. Die Rissbildung ist bei diesen Inspektionen ein Kriterium für die Schädigung einer Spannbetonschwelle. Durch Rissbildung kann es passieren, dass Betonschwellen ihre Nutzungsdauer nicht erreichen.
A series of new flame retardants (FR) based on dibenzo[d,f][1,3,2]dioxaphosphepine 6-oxide (BPPO) incorporating acrylates and benzoquinone were developed previously. In this study, we examine the fire behavior of the new flame retardants in polyisocyanurate (PIR) foams. The foam characteristics, thermal decomposition, and fire behavior are investigated. The fire properties of the foams containing BPPO-based derivatives were found to depend on the chemical structure of the substituents. We also compare our results to state-of-the-art non-halogenated FR such as triphenylphosphate and chemically similar phosphinate, i.e. 9,10-dihydro-9-oxa-10- phosphaphenanthrene-10-oxide (DOPO), based derivatives to discuss the role of the phosphorus oxidation state.
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).