Filtern
Erscheinungsjahr
Dokumenttyp
- Zeitschriftenartikel (28)
- Beitrag zu einem Tagungsband (8)
- Forschungsbericht (3)
- Sonstiges (2)
- Monografie (1)
- Buchkapitel (1)
- Posterpräsentation (1)
Sprache
- Englisch (37)
- Deutsch (6)
- Mehrsprachig (1)
Schlagworte
- Nano (6)
- OECD (6)
- Additive manufacturing (3)
- DFG SPP 2005 (3)
- EDX (3)
- Guideline (3)
- High-resolution (3)
- Nanoparticle (3)
- Nanoparticles (3)
- Prüfrichtlinie (3)
Organisationseinheit der BAM
- 4 Material und Umwelt (6)
- 4.2 Material-Mikrobiom Wechselwirkungen (6)
- 6 Materialchemie (5)
- 7 Bauwerkssicherheit (5)
- 7.4 Baustofftechnologie (5)
- 1 Analytische Chemie; Referenzmaterialien (3)
- 6.5 Synthese und Streuverfahren nanostrukturierter Materialien (3)
- 9 Komponentensicherheit (3)
- 9.6 Additive Fertigung metallischer Komponenten (3)
- 8 Zerstörungsfreie Prüfung (2)
Mobility particle size spectrometers (MPSS) belong to the essential instruments in aerosol science that determine the particle number size distribution (PNSD)in the submicrometer size range. Following calibration procedures and target uncertainties against standards and reference instruments are suggested for a complete MPSS quality assurance program: a) calibration of the CPC counting efficiency curve (within 5% for the plateau counting efficiency; within 1 nm for the 50% detection efficiency diameter), b) sizing calibration of the MPSS, using a certified polystyrene latex (PSL) particle size standard at 203 nm (within 3%), c) intercomparison of the PNSD of the MPSS (within 10% and 20% of the dN/dlogDP concentration for the particle size range 20 – 200 nm and 200 to 800 nm, respectively), and d) intercomparison of the integral PNC of the MPSS (within 10%). Furthermore, following measurement uncertainties have been investigated: a) PSL particle size standards in the range from 100-500nm match within 1% after sizing calibration at 203 nm. b) Bipolar diffusion chargers based on the radioactive nuclides Kr85, Am241 and Ni63 and a new ionizer based on corona discharge follow the recommended bipolar charge distribution, while soft X-ray-based charges may alter faster than expected. c) The use of a positive high voltage supply show a 10% better performance than a negative one. d) The intercomparison of the integral PNC of an MPSS against the total number concentration is still within the target uncertainty at an ambient pressure of approximately 500 hPa.
With a growing percentage of elderly people in the population and, correspondingly, an increasing rate of fractures of the proximal femur, the question how to stabilize medial femoral-neck fractures is gaining increasing importance. Especially in Hungary and Scandinavian countries, femoral-head-preserving surgery is advocated. However, the main problems of this procedure are re-dislocation and necrosis of the femoral head. Encouraged by two theoretical mathematical considerations, a biomechanical experiment was performed to investigate two different methods of screw fixation of medial femoral-neck fractures. The results showed that a head-preserving internal fixation with two cranial screws and a three-point supported screw at the bottom of the neck had distinct biomechanical advantages compared to conventional screw fixation. This has encouraged us to more frequently perform this minimally invasive and head-preserving surgery in Pauwels I and II medial fractures of the femoral head.
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 %.
Studienziel: Bei der zunehmenden Überalterung der Bevölkerung und der zunehmenden Inzidenz an hüftgelenknahen Oberschenkelfrakturen nimmt die Frage der Versorgung der medialen Schenkelhalsfraktur eine zunehmende Rolle ein. Vor allem aus Ungarn und den skandinavischen Ländern wird die kopferhaltende Therapie propagiert. Das Redislozieren dieser Frakturen und die Hüftkopfnekrose sind jedoch dagegenstehende Probleme. Methode: Ermutigt durch zwei theoretische mathematische Überlegungen wurden in einem biomechanischen Experiment zwei verschiedene Möglichkeiten der Verschraubung der medialen Schenkelhalsfraktur erprobt. Ergebnisse: Als Ergebnis zeigte sich, dass eine kopferhaltende Versorgung mit 2 kranial liegenden Schrauben und einer dreipunktabgestützten Schraube am Adam'schen Bogen deutliche biomechanische Vorteile hat gegenüber der herkömmlichen Verschraubung. Schlussfolgerung: Dies ermutigt uns, zunehmend die minimalinvasive und kopferhaltende Versorgung der medialen Schenkelhalsfraktur insbesondere bei Pauwels-I- und II-Verletzungen einzusetzen.
When it comes to higher accuracies, new technologies and real applications in additive manufacturing, there is one topic which cannot be avoided: The material response on the chosen processing parameters and its agreement and correspondence with literature data of the wrought material grade counterpart. In industrial Additive Manufacturing (AM) standards in terms of printing parameters, protection gas atmospheres or powder handling instructions are not obligatory. Therefore, the question must be answered whether the AM process is reproducible and reliable over different printing companies. This was the motivation to realize a round robin test between 8 European printing companies and academic partners. The consortium had printed and tested fatigue and tensile testing bars under plant-specific conditions. A commonly used cast aluminum alloy, AlSi10Mg, was chosen as test material for the PBF-LB/M process. Differences of the results between the partners and the scatter itself were discussed in detail.
When it comes to higher accuracies, new technologies and real applications in additive manufacturing, there is one topic which cannot be avoided: The material response on the chosen processing parameters and its agreement and correspondence with literature data of the wrought material grade counterpart. In industrial Additive Manufacturing (AM) standards in terms of printing parameters, protection gas atmospheres or powder handling instructions are not obligatory. Therefore, the question must be answered whether the AM process is reproducible and reliable over different printing companies. This was the motivation to realize a round robin test between 8 European printing companies and academic partners. The consortium had printed and tested fatigue and tensile testing bars under plant-specific conditions. A commonly used cast aluminum alloy, AlSi10Mg, was chosen as test material for the PBF-LB/M process. Differences of the results between the partners and the scatter itself were discussed in detail.