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- Quantitative NMR-Spektroskopie (4)
- qNMR (4)
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Troubleshooting Samples Analytics:
Impurities in products: unexpected & unwanted occurrence, unknown identity, analytical method unclear, often various analytical methods, necessary, short response time important (< 1 d), benefits: allocation of its source within hours safes cost
• Investigations planned, coordinated and documented by TSA team
• Variety of analytical methods available
Resolving overlapping peaks of multiple components. Relative primary analytical method - Fundamental relationship of qNMR.
SAF€RA ERANET – Coordination of European Research on Industrial Safety towards Smart and Sustainable Growth, in 2014 launched a joint call on “Innovating in safety and safe innovations”. The HAZPRED project “Predictive methods for determining the decomposition properties of hazardous substances: from development to experimental verification” was selected in this initiative. Main goal is the development and use of predictive methods to determine hazardous physico-chemical properties of various energetic materials (e.g. organic peroxides and self-reactive substances), e. g. thermal stability (self-accelerating decomposition temperature - SADT), explosive power (Trauzl test), heating under confinement (Koenen test), mechanical sensitiveness (impact or friction), etc. The project is based on a co-operation with INERIS (France), VSB-TUO (Czech Republic), BAM and chemical industry.
Air-coupled ultrasound has been applied increasingly as a non-destructive testing method for lightweight construction in recent years. It is particularly appropriate for composite materials being used in automotive and aviation industry. Air-coupled ultrasound transducers mostly consist of piezoelectric materials and matching layers. However, their fabrication is challenging and their signal-to-noise ratio often not sufficient for many testing requirements. To enhance the efficiency, air-coupled ultrasound transducers made of cellular polypropylene have been developed. Because of its small density and sound velocity, this piezoelectric ferroelectret matches the small acoustic impedance of air much better than matching layers applied in conventional transducers. In our contribution, we present two different methods of spherical focusing of ferroelectret transducers for the further enhancement of their performance in NDT applications. Measurements on carbon-fiber-reinforced polymer (CFRP) samples and on metal adhesive joints performed with commercially available focused air-coupled ultrasound transducers are compared to measurements executed with self-developed focused ferroelectret transducers.
Titanium dioxide is one of the most studied metal oxides due to its interesting chemical, surface, electronic and (photo)catalytic properties. These properties provide this material of multisectorial applications, ranging from healthcare, photocatalysis, smart materials with self cleaning and self sterilizing properties and solar energy harvesting (photovoltaics and water photosplitting). However it is difficult to correlate the functional properties of TiO₂ nanomaterials to the properties at single nanoparticle level due to the high polydispersity in shape, size and surface properties of the currently available TiO₂ nanoparticles (NPs) Although intensive experimental and theoretical studies have been conducted on the reactivity of different surfaces of metal oxides such as TiO₂ [1,2] much less attention is paid on the dependence of functional properties, like photocatalytic activity, dye adsorption, open circuit potential and fill factor in dye sensitized solar cells, on crystal facets in different orientations [3]. One of the goal of SETNanoMetro is the development of design rules to tune crystal facets of TiO₂ NPs in order to optimize and control functional properties. By tuning the ratio of different facets, the functional properties would be correspondingly changed. In the present work we have developed a series of design rules in order to obtain sets of anatase TiO₂ NPs with low polydispersity and to tune their shape and their size though hydrothermal processing of Ti(IV)-Triethanolamine complex in presence of different shape controllers (OH-, triethanolamine, fluoride). Through a careful experimental design the influence of many process parameters (pH, temperature, shape controller type and concentration) on the synthesis outcome (size, shape and polydispersity), a predictive soft model was developed. The model is able to predict reasonably well the synthesis outcome allowing to tune the shape factor from 5 (prisms) to 1.5 (bipyramids) to 0.2 (platelets). This allows to control the main crystal facets exposed ranging from (100) to (001).
In 2011, the German Association of Engineers (VDI) started working on a set of guidelines towards increased resource efficiency. These guidelines represent a framework that defines resource efficiency and outlines considerations for the producing industry. A special guideline for SMEs is included as well as guidelines on methodologies for evaluating resource use indicators, such as the cumulative raw material demand of products and production systems. Resource efficiency, defined here as the ratio of specific quantifiable use to natural resource consumption, can be evaluated by defining a function which expresses the specific use and quantifies the resource requirements through a set of indicators (use of raw materials, energy, water, land and ecosystem services including sinks). The results from this also depend on the system boundary parameters and the allocation rules for by-products and waste treatment options. Optimising resource use is possible at all stages of a product’s or production system’s life cycle chain (raw material extraction, production and manufacturing, use and consumption, and the end-of-life stage). VDI guidelines are widely accepted across Germany’s industrial sector and therefore represent an important means of mainstreaming resource efficiency in this target area. As well as providing a methodological framework, the guidelines describe strategies and measures towards increasing resource efficiency, and they enable industrial producers and service providers to identify potential areas of improvement. The full article presents an overview of the methodology and contents of these guidelines and discusses their impact in achieving absolute reductions in the industrial use of natural resources.
Aktueller Stand der Normung
(2015)
Increasing performance and energy efficiency of Gas Metal Arc Welding by a high power tandem process
(2015)
Standard Gas Metal Arc Welding (Standard GMAW) and a high power Tandem GMAW (TGMAW) process are evaluated with respect to energy efficiency. Current, voltage and overall equipment power are measured and energy consumption is determined. The new key performance indicator Electrical Deposition Efficiency is introduced to reflect the energy efficiency of GMAW processes. Additionally, wallplug efficiency of the equipment is determined in order to identify the overall energy consumption. Results show that energy efficiency as well as economic process performance can be significantly increased by application of the TGMAW process. Furthermore findings indicate that wall-plug efficiency of the equipment is independent of power Level and material transfer mode. A metal plate of 30 mm thick structural steel is joined by Standard GMAW and TGMAW to demonstrate the total energy savings for a real weld. Electricity consumption is reduced by more than 20 % using the high power TGMAW process.
Ultra-high performance concrete (UHPC) is characterized by outstanding compressive strength of more than 150 MPa, double of normal concrete. Furthermore UHPC has a very dense structure which leads to an extremely low permeability for fluids resulting in with a very high durability.
Further structural improvement can be achieved with thermal treatment of UHPC. Recent studies have shown that an increase in compressive strength of more than 50% is possible. Nevertheless, the accurate conditions for an optimal thermal treatment are still not determined. A multitude of parameters can be varied: Temperature, pressure, water saturation, duration of the process steps.
Primary object of this study is the optimization of the conditions for thermal treatment focused to the treatment duration at a defined temperature and pressure (185°C / 1,1MPa). Therefore, the thermally treated UHPC samples are analysed by mean of mechanical properties and phase composition.
The development of phases and strength at higher temperature differs fundamentally from other cementitious systems (like normal concrete or autoclaved aerated concrete), although the chemical composition is similar. Because of the very dense structure and the low water/cement ratio the availability of water is low. This influences the hydration process. As a consequence tobermorite is absent in thermal treated UHPC in contrast to thermally treated normal concrete or predictions based on thermodynamic modelling.
We present fundamentals for the selection of fluorescent dyes and show the challenges of the implementation of fluorescent dyes in silicone rubber materials for the production of fluorescent all-silicone rubber POF.
The following paper focuses on the evolution of micro damage in short fibre reinforced polyamide. Therefore, tube samples are subjected to uni- and biaxial fatigue loadings. The evolution of micro damage is analysed by the non-destructive method of X-ray refraction analysis with consideration of the fibre orientation distribution. For validation of the applied micro damage models, fractographic analyses are performed. Concluding some general results, it has been observed that the load ratio influences the quantitative dominance of micro damage, whereas occurring damage phenomena depend on the type of loading (i.e. tension and torsion). Thus, zones in the Haigh-diagram are detected, where the occurrence of damage mechanisms qualitatively and quantitatively changes. This is a basis for further research regarding anisotropic damage criteria.
Ober die europäischen Produktnormen für Geokunststoffe (hEN) wird gestritten: Dienen sie nur einem einheitlichen Verfahren der CE-Kennzeichnung oder werden darin alle relevanten geotechnischen Eigenschaften so verbindlich festgelegt, dass darüber hinausgehende nationale Vorschriften ungültig werden? Der Streit wurde durch ein Urteil des Europäischen Gerichtshofs weiter angefacht. Davon noch nicht betroffen ist der Deponiebau. Die Deponie ist ein besonderes Bauwerk, bei dem vor allem abfallrechtliche Regelungen beachtet werden müssen. In der deutschen Deponieverordnung wurde daher eine mit der Europäischen Kommission abgestimmte Gleichwertigkeitsklausel für CE-gekennzeichnete Bauprodukte verankert, die diese Besonderheit berücksichtigt. Wir zeigen, dass das in den hEN festgelegte Eigenschaftsspektrum der Bauprodukte im Wesentlichen nicht gleichwertig zu dem Spektrum ist, das sich aus den Anforderungen der Deponieverordnung ergibt. Die Qualitätssicherung der hEN, die nur eine zertifizierte werkseigene Produktionskontrolle jedoch keine Fremdüberwachung vorsieht, entspricht ebenfalls nicht den Anforderungen der Deponieverordnung. Eine CE-Kennzeichnung kann daher eine BAM-Zulassung nicht gleichwertig ersetzen. Auch für andere geotechnische Anwendungsgebiete gilt, dass die geltenden hEN die Geokunststoffe nicht ausreichend charakterisieren. Die Antwort auf die Frage, wie verbindlich diese mangelhaften hEN werden könnten, ist daher von weitreichender Bedeutung für die gesamte Geotechnik.