Filtern
Dokumenttyp
- Zeitschriftenartikel (6)
- Buchkapitel (1)
Schlagworte
- Hinterglasmalerei (2)
- Zerstörungsfreie Prüfung (2)
- Abdominal appendages (1)
- Adult insects (1)
- Archeometry (1)
- Archäometrie (1)
- Bauplan (1)
- Bulk metallic glasses (1)
- CT (1)
- Chemical analysis (1)
Organisationseinheit der BAM
This publication summarizes the work carried out during an IAEA coordinated research project (CRP) on safe and reliabe management of spent nuclear fuel. This work contributes to the overall goal of demonstrating the performance of spent nuclear fuel and related storage systems components over long durations, and facilitates the transfer of this knowledge to Member States. The technical areas addressed by the CRP participants were related to potential degradation mechanisms in metal casks and concrete overpacks, such as stress corrosion cracking; long term integrity and performance of the fuel cladding; thermo-mechanical behaviour of the metal seals; and long term gamma and neutron shielding capability. The participants also considered past and ongoing demonstration programmes. For each technical topic addressed the main conclusions have been drawn, including information on the development of specific monitoring and inspection techniques as well as future opportunities for closing relevant data gaps. A major achievement is also the establishment of a worldwide network of experts working on current research projects to demonstrate the long term performance of spent fuel in dry storage systems.
The aim of the research project 'Typology of
Dutch Drawing' was to establish an interdisciplinary approach
for investigating heterogeneous drawing collections.
To define a type common to a group of drawings, we
determine elements that are common to them based on style
and the use of identical materials. To that end, we investigated
about 750 Dutch drawings from the sixteenth century at the
Dresden Kupferstich-Kabinett using art historical and
scientific methods. In this work, we present a detailed
analysis of 30 drawings ascribed to the Egmont Master.
Despite their enormous diversity, the bauplan of adult winged insects (pterygotes) is remarkably conservative since the Lower Devonian: a five-segmented head, a three-segmented thorax with three pairs of walking legs and an eleven-segmented abdomen without any non-sexual appendages 1 and 2. The only known exceptions are the abdominal appendages of adult male sepsid flies on the fourth segment; however, these are also used as copulatory organs and are supposedly maintained through sexual selection [3]. Here, we report a rod-like paired appendage from the third and fourth abdominal segments in adults of the Southeast-Asian Hemiptera taxon Bennini (Figure 1A,B; Supplemental information). These are fully musculated, innervated, and movable and bear highly organized sensory and secretory units. The appendages, termed LASSO (lateral abdominal sensory and secretory organs), are consistent in topology and structure in all species studied and not sexually dimorphic. The existence of these non-sexual abdominal appendages reveals the potential of the 300 million year old conserved bauplan of insects.
Das Schwarzlot in der Hinterglasmalerei - Zerstörungsfreie Untersuchung von Kunst- und Kulturgut
(2009)
Die Bedeutung der Zerstörungsfreien Prüfung im Bereich der Kunst- und Kulturanalyse hat in den letzten Jahren deutlich
zugenommen. Mobile Untersuchungstechniken erweisen sich als besonders geeignet, da die fragilen und kostbaren Objekte
in den Museen verbleiben und somit keine Schädigungen durch Transport oder Klimawechsel erleiden können. Dieser Beitrag
möchte am Beis piel der Hinterglasmalerei die Bedeutung der naturwissenschaftlichen Analyse im Bereich der Kunstgeschichte
aufzeigen.
Der Begriff der Schwarzlotmalerei wird in der Kunstgeschichte allgemein für eine schwarze Konturmalerei verwendet. Während
der Begriff in der Glasmalerei eindeutig das Material ein mit Eisen- und Kupferoxiden schwarz gefärbtes Bleiglas bezeichnet,
steht der Begriff in der Tafelmalerei für tiefschwarze Konturen auf Goldgründen und Lüstern. Diese Modellierung ist
jedoch im Vergleich zur Glasmalerei - soweit bekannt - mit organischen Schwarzpigmenten ausgeführt.
Auch die Hinterglasmalerei, und hier insbesondere die des späten Mittelalters zeichnet sich durch eine dominierende
schwarze Konturmalerei aus.
Mittels zerstörungsfreier Röntgenfluoreszenzanalyse konnte in einer Auswahl repräsentativer Objekte Schwarzlot nachgewiesen
werden. Bezogen auf die Konturierungen ist hier eindeutig der stilistische, aber auch der maltechnische Einfluss der Glasmalerei
auf die Hinterglasmalerei ablesbar. Es ergibt sich aber ein wesentlicher Unterschied bis auf wenige Ausnahmen
wurde hier das Schwarzlot nicht eingebrannt, sondern als Kaltbemalung verwendet.
Bulk metallic glasses (BMG) are amorphous metal alloys known for their unique physical and mechanical properties. In the present study, the formation of femtosecond (fs) laser-induced periodic surface structures (LIPSS) on the Zr-based BMGs Zr46Cu46Al8, Zr61Cu25Al12Ti2, Zr52.5Cu17.9Al10Ni14.6Ti5 (Vit105) and Zr57Cu15.4Al10Ni12.6Nb5 (Vit106) was investigated as a function of their different chemical composition. For this purpose, LIPSS were generated on the sample surfaces in an air environment by fs-laser irradiation (λ = 1025 nm, τ = 300 fs, frep = 100 kHz). The surface topography was characterized by scanning electron microscopy and atomic force microscopy. Moreover, the impact of LIPSS formation on the structure and chemical surface composition was analyzed before and after fs-laser irradiation by X-ray diffraction and X-ray photoelectron spectroscopy as well as by transmission electron microscopy in combination with energy dispersive X-ray spectroscopy. Despite the different chemical composition of the investigated BMGs, the fs-laser irradiation resulted in almost similar properties of the generated LIPSS patterns. In the case of Zr61Cu25Al12Ti2, Vit105 and Vit106, the surface analysis revealed the preservation of the amorphous state of the materials during fs-laser irradiation. The study demonstrated the presence of a native oxide layer on all pristine BMGs. In addition, fs-laser irradiation results in the formation of laser-induced oxide layers of larger thickness consisting of an amorphous ZrAlCu-oxide. The precise laser-structuring of BMG surfaces on the nanoscale provides a versatile alternative to thermoplastic forming of BMG surfaces and is of particular interest for the engineering of functional material surfaces.