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- S Qualitätsinfrastruktur (19)
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- 4 Material und Umwelt (4)
- 6.3 Strukturanalytik (4)
- 1 Analytische Chemie; Referenzmaterialien (3)
- 1.4 Prozessanalytik (2)
- 4.1 Biologische Materialschädigung und Referenzorganismen (2)
- 4.5 Kunst- und Kulturgutanalyse (2)
Glühentladung optischer Ausstrahlungsspektroskopie (GDOES) wurde ursprünglich für die elementare Analyse von Größenmaterialien entwickelt. Mehrere Gruppen führten diese Methode zur Analyse von Anstrichen, Laienstapeln und dünnen Filmen durch. In den frühen Neunzigern wurde eine ISO-TC 201-Arbeitsgruppe gegründet, um Normen für alle Formen der Glühentladungsspektroskopie (GDS) zu entwickeln und die Fähigkeiten der Oberflächenchemikalien-Analyse zu beurteilen, insbesondere für die Tiefe von gestuften Systemen. Die Quantifizierung von Tiefenprofilen, d.h. die Umwandlung von Intensitäts-Zeit- Profilen in Konzentrierungs-Tiefen-Profile ist für dc-mode entwickelt worden. 1997 wurde ein VAMAS TWA 2 Vorschlag für ein Referenzanstrich für GD-OES Tiefe gemacht. Entsprechend dem VAMAS Beurteilungsverfahren wurde dieser Vorschlag 1998 mit einigen geringfügigen Änderungen genehmigt.
Die Reduzierung von Schadstoffen im Grundwasser mit reaktiven Wänden ist eine neuartiges passives Sanierungsverfahren. Die am häufigsten angewandten Dekontaminierungsprozesse sind dabei chemische Reduktion, Oxidation, Ausfällung und Sorption, die im Bericht beispielhaft dargestellt sind. Blei, Chrom und insbesondere Uran werden unter den anorganischen Schadstoffen detailliert behandelt, da solche Grundwasserverunreinigung in vielen europäischen Ländern auftreten. Baumethoden für Dichtwände und reaktive Wände weisen gemeinsame Merkmale auf. Neben den gewöhnlichen Methoden werden Bohrverfahren, deep-soil-mixing, Strahltechnologien, Brunnengalerien, Injektionssysteme und Biobarrieren angewendet, um reaktive Wände zu errichten. Die Technik der reaktiven Wände besitzt ein großes Potential für die Sanierungstechnik der Zukunft.
In der vorliegenden Arbeit wird die Ultraschallausbreitung in akustisch anisotropen, homogenen Werkstoffen mit stengelkristalliner Textur wie austenitischen Plattierungen und Schweißverbindungen, austenitischem Guss oder geschweißten Komponenten aus austenitischem Gus modelliert. Die Ergebnisse dieser Arbeit dienen als Vorgabe für Prüfanweisungen und Regelwerke, die besser als bisher an den Prüfgegenstand angepasst sind.
Englische Übersetzung von BAM Forschungsbericht 237! Keramische Werkstoffe haben auf Grund ihrer herausragenden tribologischen Eigenschaften in verschiedenen Bereichen der Produktion Anwendung gefunden und dadurch klassische Werkstoffe verdrängt. Gegenüber Metallen bieten sie bei Mangelschmierung sowohl unter Gleit- als auch grundsätzlich unter Wälzbeanspruchung Schutz vor adhäsivem Versagen. Hohe Herstellungskosten, bedingt bei der Endbearbeitung von Konturen mit verschiedenen und veränderlichen Radien, behindern die breite Marktdurchdringung. Mit der Modellverschleißprüfung - angelehnt an die DIN 50 324 - kann der bearbeitungsbedingte Einfluss auf das tribologische Verhalten unter Wälzreibung untersucht werden.
Tensile testing according to EN 10002-1 is one of the basic mechanical tests to characterise the mechanical properties of metallic materials. This testing procedure has been regularly under development for many decades in order to modify and amend it and to bring it up to an up to date standard. Today tensile testing for quality control in metals manufacturing industry is routinely performed automatically with computer controlled testing machines. Due to economical needs of industry proposals were made by a European Standard Committee to amend the standard EN 10002-1. A European research project with the acronym TENSTAND was started to validate the proposed modifications of the tensile testing standard. The work package 4 of the project was to validate the machine control characteristics. A comparison test program was started with ten partners, 4 test piece geometries and 3 test parameters for 6 materials, partly with upper and lower yield strength and partly with 0.2 % proof strength to compare experimental results according to the proposal to modify the standard EN 10002-1. Initially testing in the strain control mode was introduced as well as switching of the control mode to crosshead control 1 and switching of the testing speed at appropriate points during the test. The comparison test was evaluated statistically and scientifically. The following conclusions were derived from the comparison test and summarised as recommendations to the standard committees. The scatter of the material properties were not significantly reduced by introducing the amended testing procedure. Few of the reasons for the continuously observed scattercan be identified as follows: The material properties are observed to be widely dependent on the testing speed. As a consequence the range for the allowed testing speed must be reduced. The closed loop control was not optimised sufficiently in some tests, the use of complicated testing machine software led to misinterpretation of software commands, individual testing equipment and implementation of the tensile testing procedure led also to scatter of the material properties which lay in a range of few percent. This is blurred by the inhomogeneity of the material.
The international research project HYCREF, funded by the European Commission in the 5 th Framework programme, aimed to develop methods to prepare homogenous and stable water-, soiland waste reference materials contaminated with mineral oil hydrocarbons and to test certify the mineral oil content by gas chromatographic methods. As mineral oil products are important sources for environmental contaminations a high need exists for certified reference materials for their determination using the new gas chromatographic methods (soil: ISO/FDIS 16703, waste: ENpr 14039, water: ISO 9377-2). The experimental conditions and results for preparation and characterisation of a total of nine reference materials (3 water-, 3 soil- and 3 waste materials) are described and discussed. Target values for the reference materials were defined at the beginning of the project in order to have clear quality criteria, which could be compared with the achieved results at the end of the project. These target specifications were related to the maximum uncertainty from test certification exercises (< 5 % for soil/waste and < 10 % for water), the maximum inhomogeneity between bottles (< 3 %) and minimum requirements for stability (> 5 years for soil/waste and > 2 years for water). The feasibility studies showed that solid materials (soil, waste) could be prepared sufficiently homogenous and stable. The test certified values of the 6 solid materials comprise a wide range of mineral oil content from about 200-9000 mg/kg with expanded uncertainties between 5.7-13.1 % using a coverage factor k (k = 2). The development of new water reference materials –the so-called “spiking pills” for an offshore- and a land-based discharge water represents one of the most innovative aspects of the project. The spiking pill technology facilitates the application and storage and improves the material stability compared with aqueous materials. Additional to the preparation and test certification of the reference materials investigations on the analytical method for the determination of mineral oil hydrocarbons were performed. The results obtained in relation to the optimisation of analytical method (extraction procedure, sample pretreatment, clean-up and measurement) were provided to the respective working group of ISO/TC 190, ISO/TC 147 and CEN/TC 292 and were incorporated into the ongoing standardisation procedures. The new version of ISO/FDIS 16703 (July 2004) includes the improvements based on HYCREF results, for example the increase of the solvent/sample ratio, the removal of acetone from the organic extracts and the use of column technique instead of batch technique for clean-up.
The use of alternative oils for the lubrication of automobile engines has a potential of ecological and technical advantages. It requires the detailed knowledge of several thermophysical and viscometric properties in a large temperature range (mapping). Therefore, the following properties of up to twenty-eight different oils have been measured in the temperature range from 22 °C to 150 °C: density, heat capacity, thermal conductivity, viscosity at ambient pressure, viscosity under shear rates above 10 6 s-1, and the viscosity at elevated pressures (maximum 100 MPa). The last two have been measured with a substantially improved and a newly developed apparatus, respectively. The pressure- viscosity coefficient has been measured on four hydrocarbon-based, factory-fill oils, a paraffin oil and twenty-three alternative oils. Nine of the alternative oils are based partly or completely on esters, the other fourteen on polyglycols, two of them additionally on water.
Permeable reactive barriers (PRBs) offer an alternative as opposed to more cost-intensive active methods for groundwater remediation, e.g. pump-and-treat. Long-term performance of PRBs, however, is crucial for the technology’s success. The paper summarises the results of long-term column experiments with elemental iron (Fe0) and hydroxyapatite (HAP) as reactive materials for the removal of uranium from groundwater. Good removal results have been achieved using elemental iron with possible reaction paths being reductive precipitation and adsorption on to corrosion products of Fe0.
Because they are laid underground and because their job is to connect widely distant places, pipelines have some particular technical safety features. Chemical industry installations have fixed and instantly recognisable sites. Pipeline routes must be adapted to the constraints of infrastructure and topography, and environmental protection must be taken into account, as well as the possibility that the pipe system may be damaged by external influences. Even minor leakages can have considerable effects on watercourses and the soil, and in many cases, people are also injured. Numerous incidents abroad have proved this. In the recent past, even Germany has not been spared from sudden damage to pipelines. However, not much notice was taken of these incidents, as the resulting damage was minor and there were no fatalities. With hindsight, when seeking the causes of the damage, it is often the case that the rupture of a pipeline is associated with certain recurring features. The scene of the damage is often located near traffic infrastructure. Pipelines must of necessity cross roads and railways or are laid in parallel to such lines of communication. As a result of vibrations caused by traffic, this proximity can lead to ruptures. Road or rail accidents can lead to stresses which pipelines are unable to withstand. But a pipeline failure can have many other causes which cannot be predicted with any certainty and which even show regional particularities. In the interests of safe transport and land planning, it would therefore be worthwhile to be able to evaluate at least the possible consequences in terms of damage that might result from a pipeline rupture. There are hardly any publications on pipeline accidents, at least in German speaking countries; most of what is available is in the form of reports by the fire services. However, these are not sufficient to provide an overview of the situation. For this reason, the Federal Institute for Materials Research and Testing has evaluated many international reports of investigations and publications and summarised what they have to say about the risks inherent in pipeline failures, particularly the damage that results. This report is the outcome of this work.