Filtern
Erscheinungsjahr
Dokumenttyp
Sprache
- Englisch (24)
- Deutsch (9)
- Mehrsprachig (1)
Schlagworte
- Betonbrechsand (2)
- Magnetic domains (2)
- Müllverbrennungsasche (2)
- Nachhaltigkeit (2)
- Passive sampling (2)
- Raman microscopy (2)
- X-ray microdiffraction (2)
- Zünder (2)
- 2D nanomaterial (1)
- 3D printing (1)
Organisationseinheit der BAM
- 8 Zerstörungsfreie Prüfung (3)
- 8.6 Faseroptische Sensorik (2)
- 1 Analytische Chemie; Referenzmaterialien (1)
- 1.2 Biophotonik (1)
- 4 Material und Umwelt (1)
- 4.3 Schadstofftransfer und Umwelttechnologien (1)
- 6 Materialchemie (1)
- 6.1 Oberflächen- und Dünnschichtanalyse (1)
- 7 Bauwerkssicherheit (1)
- 7.4 Baustofftechnologie (1)
We performed spatially resolved synchrotron-induced x-ray fluorescence analyses (SY-XRF) of five silverpoint drawings from the famous `Karlsruhe sketchbook´ and a silverpoint, which is assumed to be an original one used by the Renaissance artist Hans Baldung Grien (1484-1545) himself. The silverpoint, one out of a very small number of ancient styli conserved nowadays, is fixed on the so-called `Karlsruhe sketchbook´. Measurements were executed at the FLUO-TOPO beamline at the electron storage ring ANKA. It has been shown, that SY-XRF at this beamline is nondestructive and sensitive enough for the analysis of minor and major elements in the silver strokes. This study provides new insights into this graphical technique and ancient drawing instruments: results are that three drawings have been created with a common type of silverpoint containing about (10.4 ± 0.7) wt% of Cu. In all the cases, Hg at a 10% level by weight was identified in the strokes. Presence of Hg is not due to the original silver alloy, but is a result of a general alteration phenomenon of silverpoint drawings. This fact is confirmed by the analysis of the original silverpoint, which contains only small traces of Hg. The result for the copper content of the silverpoint (10.4 ± 1.7) wt% is in good agreement with that of these three drawings. It is supposable that the silverpoint found attached today served for the creation of the corresponding drawings. Moreover, the graphical technique of Baldung is found to be continual over three decades. Only one very late drawing dated to 1543 was probably realized with another silverpoint, containing about 3 wt% of Cu. This difference in the chemical composition of drawings from the late period might be used as a more precise dating indicator of Baldung drawings that are not clearly attributed to a certain period.
Zwei Verfahren, der Unterwasser-Test und der Plate-Dent-Test, wurden hinsichtlich ihrer Eignung zur indirekten Bestimmung
der Zündstärke von Zündern untersucht. Die Einflüsse verschiedener Sekundärladungsmassen und unterschiedlichen
Hülsenmaterials von Zündern standen hierbei im Vordergrund.
Der Unterwasser-Test, bei dem als Maß für die Zündstärke die Stoß- und Blasenenergie eines Zünders ermittelt werden,
erwies sich als probate und genaue Bestimmungsmethode. Zünder mit unterschiedlichen Sekundärladungsmassen waren
eindeutig differenzierbar. Das Hülsenmaterial hatte nur einen vernachlässigbaren Einfluss auf die Ergebnisse.
Der Plate-Dent-Test, bei dem die Abmaße des gebildeten Kraters zur indirekten Bestimmung der Zündstärke herangezogen
werden, zeigte gegenteilige Effekte. Ab einem Ladungslänge-Durchmesser-Verhältnis von größer zwei war eine Differenzierung
von Zündern verschiedener Sekundärladungsmasse nicht mehr möglich. Außerdem hatte das Hülsenmaterial
einen signifikanten Einfluss auf die Kraterbildung. Der Plate-Dent-Test ist somit nur für den direkten Vergleich der Zündstärken
baugleicher Zünder z. B. unter variierenden Umweltbedingungen geeignet.---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Two procedures – the underwater test and the plate-dent-test – were examined concerning their applicability for the indirect
determination of the initiating capability of detonators. At this the focus was on the influence of varying explosive masses
and different shell material.
At the underwater test the initiating capability is determined indirectly by measurement and calculation of the shock and
bubble energy. This method proved to be effective and accurate. Detonators with different secondary charge masses could
be distinguished clearly and the shell material had only a negligible influence on the energy release.
The plate-dent-test, at which the dimensions of the formed dent are an indirect measure for the initiating capability, showed
the contrary effects. A differentiation of detonators was proved to be impossible when a relation of charge length to diameter
greater than two was reached. Furthermore, it could be shown that the shell material had significant influence on the
dent formation. Therefore, the plate-dent-test is only suitable for the direct comparison of identical detonators, e. g. under
varying environmental conditions.
Rainfall-triggered runoff is a major driver of pesticide input in streams. Only few studies have examined the suitability of passive sampling to quantify such episodic exposures. In this study, we used Empore-TM styrene-divinylbenzene reverse phase sulfonated disks (SDB disks) and event-driven water samples (EDS) to assess exposure to 15 fungicides and 4 insecticides in 17 streams in a German vineyard area during 4 rainfall events. We also conducted a microcosm experiment to determine the SDB-disk sampling rates and provide a free-software solution to derive sampling rates under time-variable exposure. Sampling rates ranged from 0.26 to 0.77 L d-1 and time-weighted average (TWA) concentrations from 0.05 to 2.11 µg/L. The 2 sampling systems were in good agreement and EDS exceeded TWA concentrations on average by a factor of 3. Our study demonstrates that passive sampling is suitable to quantify episodic exposures from polar organic pesticides.
Magnetic domains have been the subject of much scientific investigation since their theoretical existence was first postulated by P.-E. Weiss over a century ago. Up to now, the three-dimensional (3D) domain structure of bulk magnets has never been observed owing to the lack of appropriate experimental methods. Domain analysis in bulk matter thus remains one of the most challenging tasks in research on magnetic materials. All current domain observation methods are limited to studying surface domains or thin magnetic films. As the properties of magnetic materials are strongly affected by their domain structure, the development of a technique capable of investigating the shape, size and distribution of individual domains in three dimensions is of great importance. Here, we show that the novel technique of Talbot-Lau neutron tomography with inverted geometry enables direct imaging of the 3D network of magnetic domains within the bulk of FeSi crystals.
This overview article provides insight into how to apply Raman spectroscopy in combination with a confocal, optical microscope setup on polycrystalline material systems, in order to obtain quantitative information on phase distribution, grain sizes, crystal orientations and microstrain. Although the present work uses Cu(In,Ga)(S,Se)₂ absorber layers in corresponding thin-film solar cells as a model system to demonstrate the capabilities of Raman microspectroscopy, the approaches discussed may be applied to any organic or inorganic, polycrystalline materials system.
This paper gives a brief overview on3D imaging of magnetic domains with shearing grating neutron tomography. We investigated the three-dimensional distribution of magnetic domain walls in the bulk of a wedge-shaped FeSi single crystal. The width of the magnetic domains wasanalyzed at different locations within the crystal. Magnetic domains close to the tip of the wedge are much smaller than in the bulk. Furthermore, the three-dimensional shape of individual domains wasinvestigated. We discuss prospects and limitations of the applied measurement technique.
More than 5 million non-electric detonators are used annually in Germany for blasting operations. The relative usage of non-electric detonators amounts to about 50% of all civil blasting operations in Germany. BAM, as the notified body for explosives in Germany, tests non-electric detonators for the purpose of EU-type approval under the civil explosives directive, but also in the context of general investigations, e.g. when misfiring occurs. BAM has all facilities to test these detonators according to the European standard EN 13763. The presentation will cover the test facilities of BAM and address some issues of delay time accuracy. Several advantages and disadvantages of the non-electric ignition system will be discussed in the context of case investigations, and conclusions for mining operations and the advoidance of misfiring will be drawn.