Chemie und Prozesstechnik
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- Beitrag zu einem Sammelband (17) (entfernen)
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- Surface chemical analysis (2)
- Acoustic emission (1)
- Anthropologie (1)
Organisationseinheit der BAM
- 6 Materialchemie (9)
- 6.1 Oberflächen- und Dünnschichtanalyse (9)
- 8 Zerstörungsfreie Prüfung (4)
- 4 Material und Umwelt (2)
- 4.5 Kunst- und Kulturgutanalyse (2)
- 8.5 Röntgenbildgebung (2)
- Z Zentrale Dienstleistungen (2)
- Z.1 Organisation, Controlling (2)
- 8.1 Sensorik, mess- und prüftechnische Verfahren (1)
- 8.2 Zerstörungsfreie Prüfmethoden für das Bauwesen (1)
BACKGROUND CONTEXT: Targeted delivery of osteoinductive bone morphogenetic Proteins (eg, GDF5) in bioresorbable calcium phosphate cement (CPC), potentially suitable for vertebroplasty and kyphoplasty of osteoporotic vertebral fractures, may be required to counteract augmented local bone catabolism and to support complete bone regeneration. The biologically optimized GDF5 Mutant BB-1 may represent an attractive drug candidate for this purpose.
PURPOSE: The aim of the current study was to test an injectable, poly (l-lactide-co-glycolide) acid (PLGA) fiber-reinforced, brushite-forming CPC containing low-dose BB-1 in a sheep lumbar osteopenia model.
STUDY DESIGN/ SETTING: This is a prospective experimental animal study.
METHODS: Bone defects (diameter 5 mm) were generated in aged, osteopenic female sheep and were filled with fiber-reinforced CPC alone (L4; CPC+fibers) or with CPC containing different dosages.
Der Beitrag beleuchtet im Rahmen des Schwerpunktthemas "Kennzahlen als Mess- und Steuerungsinstrument in Behörden" des Arbeitskreises Steuerung & Controlling in öffentlichen Institutionen die spezifischen Aspekte der Steuerung einer Ressortforschungseinrichtung. Dabei wird am Beispiel der Bundesanstalt für Materialforschung und -prüfung das derzeit vorhandene Ziel- und Steuerungssystem dargestellt. Ausgehend vom Spannungsfeld zwischen wissenschaftlicher Freiheit und Notwendigkeit der Steuerung einer öffentlichen Einrichtung wird die Ableitung von der dreijährigen strategischen Zielvereinbarung mit dem BMWi hin zu den operativen jährlichen Abteilungszielvereinbarungen beschrieben. Zusammenfassend werden die Herausforderungen der Steuerung einer Forschungseinrichtung diskutiert.
In der anthropologischen Rudolf-Virchow-Sammlung der Berliner Gesellschaft für Anthropologie, Ethnologie und Urgeschichte (BGAEU) befindet sich eine größere Anzahl menschlicher Schädel aus dem Gebiet des heutigen Lettlands, die Mehrzahl dabei von der im Norden Lettlands am Burtnieksee gelegenen Fundstelle Riņņukalns. Der nachfolgende Aufsatz beschreibt die Gründe, warum diese Stücke in den 1870er Jahren in die Sammlung gelangt sind, und präsentiert eine anthropologische Dokumentation und Analyse der Schädelfunde vom Riņņukalns aus der Sammlung.
In Berlin befinden sich Fragmente indigener Bilderhandschriften, die Alexander von Humboldt aus Mexiko mitbrachte. Fast alle stammen sie aus der ehemaligen Sammlung des Italieners Lorenzo Boturini, deren Reste heute über mehrere Länder verstreut sind. Der hohe Fragmentierungsgrad sowie ungeklärte Fragen zur Provenienz und Genese der Bruchstücke machen es schwierig, sie zu rekontextualisieren. Um dies dennoch zu erreichen, kommen einander ergänzende moderne natur- und kulturwissenschaftliche Methoden zum Einsatz. Als Beispiel einer Neuzuordnung werden die Humboldt-Fragmente IX-XII vorgestellt. Dass die vier Bruchstücke verwandt sind, wurde schon lange vermutet, nicht jedoch, dass sie zusammen mit einem nicht mehr vorhandenen Mittelteil ein einziges Dokument gebildet haben. Die Gründe für eine derartige Rekonstruktion werden als Ergebnis der Forschungsarbeiten diskutiert.
To better understanding the failure of adhesive joints tensile tests were carried out on miniature test specimens from Norway spruce in the synchrotron. Urea-formaldehyde resin was used as adhesive. e. For comparison purposes, tensile tests were carried out on solid wood and on bonded miniature tensile shear samples with acoustic emission. The acoustic emission signals of all the experiments occurred with classified pattern recognition. This resulted in two classes of signals for each two frequency peaks. One class consisted of the low-frequency and the other of the higher-frequency peak of higher intensity, but this was essentially independent from the structure (solid wood or plywood) and size scale of the test specimens. The influence of the adhesive layers was determined on wood test specimens on laboratory scale and on miniature test specimens with an adhesive layer and selected fiber orientations. This gave evidence that the sound emission signals from the failure of the adhesive layer presumably of the class with low frequency signals peak in the range of services can be assigned.
A variety of methods used to prepare nano-objects for surface analysis are described along with information about when they might be best applied. Intrinsic properties of NPs which complicate their characterization and need to be considered when planning for surface or other analyses of NPs are identified, including challenges associated with reproducible synthesis and functionalization of the particles as well as their dynamic nature. The relevant information about the sample preparation processes, along with analysis details and data that need to be added to the collection of material provenance information is identified. Examples of protocols that have been successfully used for preparation of nano-objects for surface analysis are included in an annex.
This chapter provides an introduction in secondary ion mass spectrometry as one of the leading surface chemical analysis and imaging techniques with molecular specificity in the field of material sciences. The physical basics of the technique are explained along with a description of the typical instrumental setups and their modes of operation. The application paragraph specifically focuses on nanoparticle analysis by SIMS in terms of surface spectrometry, imaging, analysis in organic and complex media, and depth profiling.
A review of the existing literature is provided, and selected studies are showcased. Limitations and pitfalls as well as current technical developments of SIMS application in nanoparticle surface chemical analysis are equally discussed.
Introduction
(2020)
The purpose of this book is to provide a comprehensive collection of analytical methods that are commonly used to measure nanoparticles, providing information on one, or more, property of importance. The chapters provide up-to-date information and guidance on the use of these techniques, detailing the manner in which they may be reliably employed. Within this chapter, we detail the rationale and context of the whole book, which is driven by the observation of a low level of reproducibility in nanoparticle research. The aim of the book is to encourage awareness of both the strengths and weaknesses of the various methods used to measure nanoparticles and raise awareness of the range of methods that are available. The editors of the book have, for many years, been engaged in European projects and standardization activities concerned with nanoparticle analysis and have identified authors who are experts in the various methods included within the book. This has produced a book that can be used as a definitive guide to current best practice in nanoparticle measurement.
Conclusions and perspectives
(2020)
This chapter briefly summarizes the methods selected within this book for the characterization of nanoparticles with regard to commonly accessible properties: nanoparticle size and size distribution, shape, surface area, surface charge, aggregation state, structure, chemical composition, surface chemistry, and nanoparticle number concentration. Current progress of measurement and analysis, as far as possible according to standard operation procedures, has been the focus of this work. A number of new and less commonly used methods have not been covered, and we outline some of these in this chapter. Future challenges such as automated measurement and analysis, read-across approaches for the prediction of properties, knowledge of measurement uncertainties, the need for certified reference materials, and the necessity to complement measurements methods to obtain more reliable results are covered, and the unmet measurement requirements for real-world nanoparticles are described.