Filtern
Erscheinungsjahr
Dokumenttyp
Schlagworte
- ToF-SIMS (3)
- XPS (3)
- Polycarbonate (2)
- AES (1)
- BAM-L200 (1)
- Building of the storage facility (1)
- CRM (1)
- Certified reference material (1)
- Chemical compatibility testing (1)
- Dangerous goods packagings (1)
- Dauerüberwachung (1)
- Dynamische Untersuchungen (1)
- EDX (1)
- ESCR (1)
- Environmental stress cracking (1)
- Fe-Ni alloy (1)
- HDPE (1)
- Imaging (1)
- Imaging surface analysis (1)
- Interim storage facility (1)
- Key comparison (1)
- Lateral resolution (1)
- Micro-fluidic device (1)
- Mikrofluidik (1)
- Nanoanalytik (1)
- Nuclear reactor compartments of submarines (1)
- Oxygen plasma (1)
- PMMA (1)
- Plasma treatment (1)
- Principal component analysis (1)
- Quantification (1)
- Referenzmaterial (1)
- STXM (1)
- Sharpness (1)
- Standardisation (1)
- Traceability (1)
- Tragfähigkeit von Brücken (1)
- Transportation of heavy compartments (1)
- Uncertainty (1)
- Verkehrslasten (1)
- Wettability (1)
- XPEEM (1)
- baulicher Zustand (1)
Referat:
Nach dem gegenwärtigen Stand der Prognosen wird in den nächsten 10 bis 15 Jahren eine Zunahme des Güterverkehrs in Deutschland um 50 % angenommen. Im Jahre 2001 wurden 85 % aller transportierten Güter auf der Straße bewegt. Dies bedeutet, daß die vorhandenen Ingenieurbauwerke innerhalb der Verkehrsinfrastruktur mit zunehmendem Alter immer höhere Belastungen ertragen müssen. Zum anderen werden die zur Verfügung stehenden Mittel zum Ersatz dieser Infrastrukturbauwerke immer geringer. Eine aktuelle Bewertung dieser Bauwerke bezüglich ihrer Sicherheit und Gebrauchsfähigkeit erfordert deshalb zusätzliche Informationen hinsichtlich Art und Umfang eventuell vorhandener Schäden, deren Auswirkung auf die aktuelle Tragwirkung und Tragfähigkeit sowie Information über die vergangenen, gegenwärtigen und zukünftigen Lasteinwirkungen.
Ultra-short pulse laser seeding techniques for silicon crystallite growth on amorphous substrates
(1999)
An international interlaboratory comparison of the measurement capabilities of four National Metrology Institutes (NMIs) and one Designated Institute (DI) in the determination of the chemical composition of thin Fe-Ni alloy films was conducted via a key comparison (K-67) of the Surface Analysis Working Group of the Consultative Committee for Amount of Substance. This comparison was made using XPS (four laboratories) and AES (one laboratory) measurements. The uncertainty budget of the measured chemical composition of a thin alloy film was dominated by the uncertainty of the certified composition of a reference specimen which had been determined by inductively coupled plasma mass spectrometry using the isotope dilution method. Pilot study P-98 showed that the quantification using relative sensitivity factors (RSFs) of Fe and Ni derived from an alloy reference sample results in much more accurate result in comparison to an approach using RSFs derived from pure Fe and Ni films. The individual expanded uncertainties of the participants in the K-67 comparison were found to be between 2.88 and 3.40 atomic %. The uncertainty of the key comparison reference value (KCRV) calculated from individual standard deviations and a coverage factor (k) of 2 was 1.23 atomic %.
Validierte Messverfahren für die nichtgeometrische Größe Hydrophilie - Anwendung in der Mikrofluidik
(2011)
The wettability of the surfaces inside the microchannels of a microfluidic device is an important property considering a liquid flows through them. Contact angle measurements usually applied to test the wettability of surfaces cannot be used for an analysis of microchannel walls within microfluidic devices. A workaround is the use of surface analytical methods, which are able to reach points of interest in microchannels and may provide information on the surface chemistry established there. In calibrating these methods by using flat polymer wafers, where the contact angle can be measured as usual, data measured in real microchannels can be evaluated in terms of wetting properties. Reference wafers of bisphenol-A polycarbonate, a polymeric material that is often used in fluidic microdevice fabrication, were treated under different oxygen plasma conditions. The modified surfaces were characterized by using XPS, time of flight (ToF)-SIMS and atomic force microscope (AFM). Surface chemistry and surface topography have been correlated with contact angle measurements. In addition, effects of ageing or rinsing after plasma treatment have also been investigated.
Recently, time-of-flight secondary ion mass spectrometry (ToF-SIMS) and X-ray photoelectron spectroscopy (XPS) instrumentation has been used to address areas of interest within micro-fluidic devices providing full access to the surface chemistry established at the bottom of micro-channels therein. After careful calibration, information on surface chemistry as obtained by ToF-SIMS or XPS can be interpreted in terms of wettability expressed as contact angles which are then characteristic for the inner walls of micro-channels. Standard contact angle measurement is not applicable in micro-channels. The approach has been demonstrated to be successful with two different micro-fluidic devices hot embossed into high-end quality poly(methyl methacrylate) (PMMA) or Polycarbonate wafers. A pre-selected surface chemistry at micro-channel walls can be established by plasma technologies but ageing and rinsing effects have to be under control. A combination of ToF-SIMS, XPS and contact angle measurement techniques has been demonstrated to provide the required information. Finally, it is shown by ToF-SIMS and XPS analysis that in the production of micro-fluidic parts during practical processing using hot embossing technologies, material originating from cover foils will reside on the polymer wafer's surface. Moreover, residues of releasing agents as silicone oil used during processing can be detected by ToF-SIMS. Both cover foil residues and silicones are issues of trouble shooting in micro-fluidics because they will change contact angles efficiently.
The certified reference material BAM-L200, a nanoscale stripe pattern for length calibration and specification of lateral resolution, is described. BAM-L200 is prepared from a cross-sectioned epitaxially grown layer stack of AlxGa1–xAs and InxGa1–xAs on a GaAs substrate. The surface of BAM-L200 provides a flat pattern with stripe widths ranging down to 1 nm. Calibration distances, grating periods and stripe widths have been certified by TEM with traceability to the length unit. The combination of gratings, isolated narrow stripes and sharp edges of wide stripes offers plenty of options for the determination of lateral resolution, sharpness and calibration of length scale at selected settings of imaging surface-analytical instruments. The feasibility of the reference material for an analysis of the lateral resolution is demonstrated in detail by evaluation of ToF-SIMS, AES and EDX images. Other applications developed in the community are summarized, too. BAM-L200 fully supports the implementation of the revised International Standard ISO 18516 (in preparation) which is based on knowledge outlined in the Technical Report ISO/TR 19319:2013.
Safety risks may ensue when the chemicals contained in polyethylene packagingsa age and damage them. To prevent subsequent accidents, the European Dangerous Goods Regulations have laid down requirements for testing the chemical compatibility of liquid dangerous goods transported in polyethylene packagings. The test procedures include 6 months in which the chemical is prestored in the packaging. After this time, the respective design-type tests are performed. Alternative methods with so-called standard liquids, simulating the different types of damaging effects, are also possible. If a packaging has successfully passed the design type tests with a standard liquid, other dangerous goods may also be transported in this packaging, as long as it is demonstrated that they have a less damaging effect than the standard liquid. However, in this area there is only little information and research available.
A new potentially effective and time-saving method for comparing the stress crack damaging influence of liquids with standard liquids was proposed by a major German chemical company.
The validation of this method, which was carried out on two polyethylene materials, showed the general applicability of the method. Two kinds of wetting solutions were applied to simulate cracking under stress.
The influence of prestorage, test temperatures, wetting agents and material was examined. FEM calculations were carried out to ascertain the influence of the sample shape.