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Organisationseinheit der BAM
- 3 Gefahrgutumschließungen; Energiespeicher (9)
- 3.2 Gefahrguttanks und Unfallmechanik (4)
- 7 Bauwerkssicherheit (4)
- 3.0 Abteilungsleitung und andere (3)
- 8 Zerstörungsfreie Prüfung (3)
- 2 Prozess- und Anlagensicherheit (2)
- 3.3 Sicherheit von Transportbehältern (2)
- 7.4 Baustofftechnologie (2)
- 2.0 Abteilungsleitung und andere (1)
- 2.3 Einstufung von Gefahrstoffen und -gütern (1)
In line with the industrial trend of additive manufacturing, cold spray as a non-laser-based process is becoming increasingly important for many fields of application. For the evaluation of additive manufacturing of winding components made of copper for large electrical high-voltage machines, material and component properties such as electrical conductivity, mechanical load capacity and the component size that can be produced are of particular importance. In this context, the cold spray process offers advantages over laser-based additive manufacturing processes such as laser powder bed fusion (LPBF) or laser cladding by using the kinetic energy of the copper powder particles to generate particle cohesion. To investigate the electrical conductivity as well as the mechanical load capacity of cold spray parts, specimens were machined out of cold sprayed bulk copper deposits. The characteristic values were obtained with regard to the direction of deposition, which is defined by the direction of the robot’s movement. Thus, for the investigation of the component properties, specimens were provided that had been produced both longitudinally and transversely as well as orthogonally to the direction of deposition. The results of the investigations show that both the electrical conductivity and the mechanical load capacity of the specimen have a strong preferential direction of the specimen orientation with respect to the direction of deposition. Furthermore, it could be shown that by increasing the deposition height, there is an increasing oxygen content in the sample material, combined with increasingly significant defect networks. These effects have a negative impact on the electrical conductivity as well as on the mechanical load capacity. As a conclusion, further need for investigation is identified in the optimization of the process parameters as well as in the deposition strategy for the additive manufacturing of large-volume components with cold spray.
To improve ultrasonic imaging of concrete structures, we transferred a seismic migration technique, the Reverse Time Migration (RTM), to non-destructive testing. A 2D elastic RTM algorithm was tested on synthetic ultrasonic echo data. Compared to the typically used synthetic aperture focusing technique (SAFT) as well as our acoustic RTM algorithm, the presented elastic RTM results show an enhancement in imaging vertical reflectors and complex features inside the 2D numerical concrete model.
The 5G technology promises real time data transmission for industrial processes, autonomous driving, virtual and augmented reality, E-health applications and many more. The Low Temperature Co-fired Ceramics (LTCC) technology is well suited for the manufacturing of microelectronic components for such applications. Still, improvement of the technology such as further miniaturization is required. This study focuses on the characterization of inner metallization of LTCC multilayer modules, especially on the vertical interconnect access (VIA). Critical considerations for this characterization are delamination, pore clustering in and at the edge of the VIA, deformation, and stacking offset. A LTCC multilayer consisting of a glassy crystalline matrix with silver based VIAs was investigated by synchrotron x-ray tomography (CT). The aim of this study is to propose a multitude of structural characteristic values to maximize the information gained from the available dataset. Data analysis has been done with the open source software ImageJ as well as several additional plugins. The high-resolution CT data was evaluated through 2D slices for accessibility reasons. The segmentation of all 2000 slices to assess the different regions e.g. pores, silver and glass ceramic was done by a supervised machine learning algorithm. A quantitative evaluation of shape, deformation, and porosity of the VIA with respect to its dimensions is presented and the suitability of the characterization approach is assessed.
Laboratory test results are of vital importance for correctly classifying and labelling chemicals as “hazardous” as defined in the UN Globally Harmonized System (GHS) / EC CLP Regulation or as “dangerous goods” as defined in the UN Recommendations on the Transport of Dangerous Goods. Interlaboratory tests play a decisive role in assessing the reliability of laboratory test results. Interlaboratory tests performed over the last 10 years have examined different laboratory test methods. After analysing the results of these interlaboratory tests, the following conclusions can be drawn:
1. There is a need for improvement and validation for all laboratory test methods examined.
2. To avoid any discrepancy concerning the classification and labelling of chemicals, the use of validated laboratory test methods should be state of the art, with the results accompanied by the measurement uncertainty and (if applicable) the probability of incorrect classification.
This paper addresses the probability of correct/incorrect classification (for example, as dangerous goods) on the basis of the measurement deviation obtained from interlaboratory tests performed by the Centre for quality assurance for testing of dangerous goods and hazardous substances (CEQAT-DGHS) to validate laboratory test methods. This paper outlines typical results (e.g. so-called “Shark profiles” – the probability of incorrect classification as a function of the true value estimated from interlaboratory test data) as well as general conclusions and steps to be taken to guarantee that laboratory test results are fit for purpose and of high quality.
In Deutschland fallen jährlich 20 Millionen Tonnen Altpapier an. 75 % davon werden dem Recyclingprozess zugeführt. Dabei bleiben Prozessrückstände wie Deinkingschlämme, Sortierrückstände und Faserreststoffe übrig. Zusammengefasst als Papierschlamm verwerten die Recycler diesen Reststoff thermisch in dezentralen Heizkraftwerken. Die dabei anfallende Papierasche hat mit den Anteilen der Hauptoxide von 59 M.-% CaO, 22 M.-% SiO2 und 13 M.-% Al2O3 eine ähnliche chemische Zusammensetzung wie Portlandzement, wobei sich die Mineralphasen unterscheiden. Durch eine Aktivierung der Papierasche können jedoch hydraulisch aktive Phasen wie Mayenit (C7A12) und Belit (C2S) erzeugt werden. Die Mineralphase Mayenit reagiert schnell mit Wasser zu Calciumaluminathydraten, wodurch der Bindemittelleim schnell ansteift. Die festigkeitsbildenden Calciumsilicathydrate (CSH) in Bindemittelleimen entstehen bei einer späteren Reaktion von Belit mit Wasser.
Zur Aktivierung dient eine hydrothermale Calcinierung. Dabei wird Papierasche mit einer Aktivatorlösung (Wasser oder KOH) gemischt und bei 200 °C hydrothermal behandelt, wobei sich Hydratphasen ausbilden. Diese Zwischenprodukte dehydratisieren durch eine anschließende Calcinierung zu reaktiven Calciumsilicaten und Calciumaluminaten. Wie sich die Parameter des Aktivierungsprozesses auf die Mineralphasen auswirken, war Fokus der Untersuchungen. Mit thermogravimetrischen Analysen der Zwischenprodukte konnten die Reaktionsprodukte nach dem hydrothermalen Prozessschritt bestimmt werden. Den größten Einfluss auf den Mineralphasenbestand hat hierbei die Alkalität der Aktivatorlösung. Im zweiten Prozessschritt, der Calcinierung, ist die Temperatur der wesentliche Faktor für die Ausbildung reaktiver Phasen. Die Ergebnisse kalorimetrischer Untersuchungen an Leimen aus den calcinierten Proben dienten der Auswahl der optimalen Calcinierungstemperatur. Die gesamte Reaktionswärme war für die Proben, welche bei einer Calcinierungstemperatur zwischen 700-800 °C hergestellt wurden, am höchsten.
Reinforced concrete (RC) is used as structural material in most diverse civil engineering applications. For the variability of its physical properties it is still an engineering challenge to meet all necessary requirements for the prediction of dynamic effects under impact loading. In this paper, investigations are shown within the scope of quantifying and evaluating the damage caused by an impact. The experimental investigations are performed in the field of low- and medium-velocity impact. The chosen flat nose shape results in small penetrations on the top side and scabbing on the bottom side. The plate is scanned with an adapted planar tomographic examination after the impact, and the damage is analysed, afterwards. Cracks and spalling are made visible with a reconstruction. The numerical model validated on the tomographic results justifies the application for further predictions of the damage description.
Auf Initiative der Europäischen Kommission ist die Europäische Eisenbahn Agentur seit einigen Jahren damit beauftragt, in Zusammenarbeit mit einer Reihe von Expertinnen und Experten aus Europa harmonisierte Leitlinien für das Risikomanagement im Gefahrgutsektor zu entwickeln und fortzuschreiben.
Der Vortrag informiert über die Entwicklung und den Stand der Arbeiten zum „Inland Transport of Dangerous Goods Risk Management Framework“ (RMF):
- Warum gibt es das Risk Management Framework?
- Wer ist an der Entwicklung beteiligt?
- Wie ist das Risk Management Framework aufgebaut, an wen richtet es sich und was beinhaltet es?
- Welche grundsätzlichen Fragen sind zu klären?
- Wie geht es weiter?
Unter den von Humboldt in Amerika erworbenen Schriftstücken der Kolonialzeit findet sich eine Tributliste aus dem Jahr 1569, die der Otomí Bevölkerung aus dem Ort Mizquahuala im Staat Hidalgo/ Mexiko zugeordnet wird. Sie ist in Form eines Kalenders ausgeführt, Wochentage und verschiedene Produkte lassen sich unterscheiden. Eduard Seler beschreibt dieses Manuskript zusammen mit einer weiteren Tributliste, die in Inhalt und Zeichnung anders gestaltet ist, jedoch ebenfalls aus dieser Region stammt.
Mit den für die Analyse von Manuskripten bewährten Untersuchungsmethoden werden Papier und Farbmittel identifiziert. Hierzu zählen Raman-, FTIR-, Röntgenfluoreszenz- und VIS- Spektroskopie. Charakteristisch für die Herstellung von schriftlichen Dokumenten in der Kolonialzeit von Amerika ist die Verwendung von indigenem Material wie Papier aus Baumrinde und Pflanzenfarben zusammen mit den aus Europa bekannten Materialien. Geklärt wird, welche Auswahl von Farbstoffen zur Herstellung der Dokumente genutzt wurde, die diese als Gruppe klassifizieren könnte.
Die den beiden Fragmenten zugeordneten Farbmaterialien sowie formale und inhaltliche Aspekte lassen vermuten, dass zwei weitere Schriftstücke der Berliner Sammlung `Manuscripta Americana´, deren Herkunft nicht bekannt ist, mit ihnen in Beziehung gebracht werden können. Stilistisch gleiche Fragmente befinden sich zudem in Mexiko, Paris und den USA.
Im Vergleich dieser Fragmente untereinander wird diskutiert, inwieweit die über die Materialanalyse identifizierten spezifischen Farbstoffe einen Hinweis auf eine gemeinsame lokale Herkunft zulassen.
The Reduced Volume Method (RVM) has been used to evaluate the multiscale fibre break model developed at Mines ParisTech. It allows the model to be assigned only at certain part of the structures without necessarily compromising the final prediction. An attempt to model a simple unidirectional composite structure has also been carried out and gave a satisfying result. This paper deals with the application of the RVM to real scale type IV composite cylinders, where its stacking sequence was evaluated through micro-CT scans conducted with the collaboration of the University of Southampton. Two modelling geometries were evaluated and compared with the corresponding experimental results.
We analyzed the results of high-energy X-ray CT scans for three 20×16×16 in. block samples of Indiana limestone from our recent radial acidizing experiments with HCl. CT scans were done for complete samples, and 3D images of internal dissolution patterns were built. Each 3D image consists of submillimeter-size voxels to capture fine details of individual wormholes.
The obtained 3D images of acidized blocks allow us to observe from various angles the details of the wormholes obtained in the three experiments, which demonstrated wide pore-volume-to-breakthrough (PVBT) range with three different injection rates. Also, variation of the CT number reveals the presence of depositional layers in all block samples, and the obtained CT images were used to interpret the effect that rock layers might have on wormhole penetration at different injection rates.
Further, the built voxel models were used to calculate the radial distributions of dissolved rock volume, which otherwise are not obvious for such complex branched structures as wormholes. We observed how varied experimental conditions affected those distributions. The radial distributions were found very similar across the samples, which suggested the way to detect the effective wormhole penetration depth.