Analytische Chemie
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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)
- 1 Analytische Chemie; Referenzmaterialien (1)
- 1.4 Prozessanalytik (1)
- 8.1 Sensorik, mess- und prüftechnische Verfahren (1)
- 8.2 Zerstörungsfreie Prüfmethoden für das Bauwesen (1)
The program PowderCell is a crystallographic tool for visualization of Crystal structures. However, it offers also non-conventional features like the fulautomatical generation of subgroups or the consideration of non-standard settings of space-group types. On the one Hand the program is very useful for non-crystallographers who like to get an impression of the atomic arrangement within the unit cell. But also for crystallographers it is recommendable because it contains a lot of additional information which can be extracted and used like data given in the International Tables for Crystallography, Vol. A. However, the most important advantage of the program is the simultaneous calculation of the X-ray or neutron diffraction powder patterns for a mixture of up to 10 crystalline phases. Between more than 7 different characteristic radiations can be chosen and their influence on the resulting powder pattern can be studied. Furthermore, experimental diffractograms can be analysed using a refinement procedure. The implemented LeBail-algorithm allows the investigation of unknown phases. In combination with the refinement algorithm an interface to Shelx offers the possibility for a step by step ab initio structure analysis. Certainly, the user-friendly shell is one reason that especially users who are not so familar with space-group symmetry, crystal structure data or diffractometry use this powerful tool for the solution of scientific or analytical problems as well as in teaching.
X-ray stress analysis on crystalline materials is based on the determination of elastic lattice strains. The strains described by the shift of peak positions are converted to stresses by the means of theory of elasticity. The development of the sin2ψ-method of X-ray stress analysis introduced an enormous progress in X-ray stress analysis during the last decades. This report outlines some important elements of X-ray physics and fundamentals of theory of elasticity. The Standard measuring procedure are described and special experimental differences to the common powder diffractometry are outlined.
In this paper we present the results of imaging studies of ancient Egyptian metallic artifacts using micro-Computed Tomography (micro-CT). Micro-CT is a non-destructive imaging method with high spatial resolution, which enables the examination of the internal structure of objects. It is thus especially suitable for the investigation of cultural heritage and archaeological findings, when it is not possible to sample or difficult to manipulate the object. Using specialized software for 3D visualization and segmentation, data sets of two objects were analyzed. We gained a clear view of the inner structure of a metallic archaeological artifact from the necropolis of Abusir el-Meleq, which is believed to be very ancient in the Egyptian archaeological context (from the Predynastic Era), and were able to distinguish its different omponents under the thick layers of external concretions. These components give hints about the production technology of the object. We also investigated the contents of a closed metal box found near Abusir dated to the Late/Greco-Roman Period. The identified Content corresponds either to sediments or to mineral remains of the original content of the box. Both artifacts are from excavations conducted in Egypt and are part of the archeological collection of the Ägyptisches Museum und Papyrussammlung in Berlin.
Die naturwissenschaftliche Analyse historischer Materialen ermöglicht die Beantwortung kulturhistorischer Fragestellungen, die mit kunsthistorischen oder archäologischen Ansätzen allein nicht zu leisten sind. In dieser Studie wurden sechs römische Münzen mit unterschiedlich stark ausgeprägten Korrosionsschichten an unbehandelten und polierten Stellen mit vier zerstörungsfreien analytischen Methoden untersucht: Hoch- und Niederenergie Protonen Induzierter Röntgenemission (HE-/PIXE), Synchrotronstrahlungsinduzierte-Röntgenfluoreszenzanalyse (SY-RFA) und Mikro-Röntgenfluoreszenzanalyse (Mikro-RFA) mit einem mobilen Gerät. Aufgrund von Unterschieden in den Messbedingungen und dem Einfluss der Patina-Schichten auf diese ergaben sich nur für wenige Elemente Übereinstimmungen in den quantitativen Daten. Zur Validierung zukünftiger Messkampagnen mit verschiedenen Methoden sind daher Vergleichstudien unerlässlich.
The International Qumran project conducted at the BAM Federal Institute for Materials Research and Testing in 2007–10 aimed at establishing an optimal methodology for an accurate characterization of the Dead Sea Scrolls to address such questions as archaeological provenance, origin, and attribution of fragments to a specific sheet (Rabin 2013). Using equipment of various degrees of complexity we have shown that part of the historic information stored in the material can be revealed by proper characterization of the material. The on-site investigation of the Dead Sea Scrolls fragments from The Schøyen Collection in October 2012 offered the first chance to test this methodology in a field study. For the first time, we used mobile and non-invasive technology exclusively, since we could not transport all of our laboratory equipment to Norway for this project. Moreover, besides the technical limitations dictated by the available equipment, we had to cope with limited time: it was impossible to perform the number of scans required for optimal characterization of over 30 fragments within the fourteen days available. Nevertheless this study presents an important step in the material analysis of the Dead Sea Scrolls, since the devices we used are easily transportable, well known, and easily accessible throughout the world.
We have obtained a minute amount of dry ink scratched from the bronze inkwell MS 1655/2. The powder was stored between two glass slides to minimize contamination. For micro analysis by FTIR a sample of the ink powder was transferred into a diamond cell while for confocal Raman spectroscopy a micro sample was placed onto sticky tape. The same portion of the sample was also investigated by scanning electron microscopy, where the elements distribution was determined by EDX.
The aim of our work was to check whether the assumption that the jar was discovered in Qumran can be substantiated. In order to establish the archaeological provenance of the jar we conducted a series of analytical tests on samples of material collected from the jar in April and June 2009. The samples were either found loose within the jar, these being probably constituted by remnants of its original contents, or were clay detached from the inner and outer surface of the jar. In addition, a portion of sand deposit coating the inside of the jar handles was analysed.
Our current projects focus on the material analysis of the writing materials
kept in the Taylor-Schechter Collection at Cambridge University Library,
which houses the largest collection of Cairo Geniza fragments, about 190,000.
Although Geniza manuscripts have attracted a great deal of scholarly attention,
the material aspects of these documents seem to have been largely neglected.
The current study aims to obtain information on the composition of the writing
supports and the inks that were used, the production of the original manuscripts
and the history of their degradation. The collected data should supplement the
description based on Hebrew palaeography and codicology. Moreover, a characterisation
of the writing materials would provide insights on trade, local production
techniques and social structures. The tabulated results have the potential to
be used as geo-chronological markers if sufficient data is collected.
For our study, we chose Hebrew legal documents and letters from three communities
that co-existed in Fustat (today Cairo) in the 11th century: the Jerusalemite
(or ‘Palestinian’) community, the Babylonian community and the Karaites, three
different communities with different scribal traditions. In addition to this, we
studied non-biblical scrolls attributed to the Palestinian and Babylonian communities.
The question we addressed was whether we can correlate the use of a
specific type of ink to an objective criterion.
For our analysis at Cambridge University Library, we used a number of protocols
developed at BAM (Bundesanstalt für Materialforschung und -prüfung) in
Berlin and at the Centre for Study of Manuscript Cultures, University of Hamburg
(CSMC). These include reflectographic examination followed by non-destructive
X-ray fluorescence (XRF) analysis using transportable instruments so that the
analysis can be carried out in situ.
We have illustrated our approach here by providing two examples. The first one
describes our investigation of the leather fragment containing a portion of the
Babylonian Talmud on its hair side (TS Misc.26.53.17). The second example illustrates
our ability to compare iron-gall inks using the XRF method. In this case,
we explored the question of the codicological attribution of three fragments (TS
F17.4, TS 12.755 and TS 12.756) to the same Talmud manuscript.
Materialanalytische Verfahren gewinnen zunehmend an Bedeutung bei der Beantwortung kulturhistorischer Fragestellungen, etwa nach Werkstatt, Alter, Künstler oder Provenienz eines Artefakts. Auch die Entwicklung geeigneter Restaurierungs- und Konservierungskonzepte bedarf dieser Grundlage ebenso wie die Beurteilung hinsichtlich der Frage nach Fälschung oder Kopie. Dem kunsttechnologisch orientierten Analytiker steht heute eine eindrucksvolle Bandbreite instrumenteller Methoden zur Verfügung, um die beiden Hauptkomponenten verwendeter Malfarben zu identifizieren, d.h. Farb- und Bindemittel. Der nachfolgende Aufsatz enthält eine kurze Zusammenstellung geeigneter Analyseverfahren, die üblicherweise bei der Untersuchung von Gemälden Verwendung finden.
Die Zusammensetzung der Malfarben Heinrich Campendonks in ihrer Kombination aus Farbpigmenten, Bindemitteln und Metallpulvern ist bislang nahezu unerforscht. Lediglich
für wenige Leinwandgemälde des Künstlers liegen publizierte Untersuchungen zu den Farbmitteln vor. Materialanalysen zu den Hinterglasarbeiten des Malers fehlten bisher. Im Rahmen eines Forschungs- und Restaurierungsprojektes im Zeitraum von 2014 bis 2016 wurden naturwissenschaftliche Untersuchungen an ausgewählten Hinterglasbildern durchgeführt, deren Ergebnisse in diesem Aufsatz vorgestellten werden. Die Untersuchungen erfolgten zunächst nicht-invasiv mit VIS-Spektroskopie, Röntgenfluoreszenzanalyse sowie Ramanspektroskopie, weiterhin mit Licht- und Fluoreszenzmikroskopie, Rasterelektronenmikroskopie mit energiedispersiver Röntgenmikroanalyse, Fourier-Transformations-Infrarotspektroskopie, Raman-Mikroskopie und Gas-Chromatografie/Massenspektrometrie.
Eine maltechnische Eigenart der Hinterglasbilder Heinrich Campendonks liegt in der Verwendung von fein gemahlenen unedlen Metallen wie Kupfer, Zinn, Zink, Aluminium sowie Metalllegierungen wie Messing. Sie waren seinerzeit entweder in Pulverform oder als gebrauchsfertige Malfarben im Handel erhältlich und wurden meist Bronzen, vereinzelt auch Brokatbronzen, Metall- oder Brokatfarben genannt. Der Aufsatz stellt die wesentlichen Aspekte der Metalleffektpigmente in Campendonks Werk vor.
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.
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.
Digitalisierung und Industrie 4.0 verändern komplette Geschäftsmodelle, heben neue Effizienzpotenziale und stärken die Wettbewerbsfähigkeit. Auf dem 57. Tutzing-Symposion vom 15.–18.04.2018 wurde mit Vorträgen und Kreativworkshops erkundet, welche speziellen Anforderungen die Prozessindustrie hat, welche digitalen Innovationen bereits umgesetzt wurden und wo noch Handlungsbedarf besteht. Ein Workshop befasste sich mit den Themenfeldern Datenkonzepte, Datenanalyse, Big Data und künstliche Intelligenz.
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.
In this chapter sample preparation, image acquisition, and nanoparticle size and shape characterization methods using the scanning electron microscope (SEM) in reflective and transmitted working modes are described. These help in obtaining reliable, highly repeatable results. The best solutions vary case-by-case and depend on the raw (powdered or suspension) nanoparticle material, the required measurement uncertainty and on the performance of the SEM.
Characterization of nanomaterials by transmission electron microscopy - Measurement procedures
(2020)
In this chapter, approaches are proposed for the descriptive and quantitative characterization of nano-objects with nanometer resolution. Measurements are based on the analysis of the characteristics of 2D projections of individual particles visualized on transmission electron micrographs.
Incorporation of spectroscopic methods (EDS and EELS) for elemental analysis of nano-objects is recommended to identify subpopulations of nano-objects in mixtures based on their chemical composition. The focus lies on the determination of physicochemical properties which are essential in a legislatory and regulatory context to define the material as a nanomaterial (NM), and to assess its safety and toxicological potential, using widely accessible equipment.
This chapter provides an overview of what standards are, why they are important, and how they are developed. There is a focus on the work of standards committees relevant to nanotechnology measurement and characterization with tables detailing the standards that are currently available for a large number of different techniques, materials, and applications at the nanoscale.
Auger electron spectroscopy
(2020)
An introduction in the application of Auger Electron Spectroscopy to surface chemical analysis of nanoparticles is given. Auger Electron Spectroscopy is a mature method in the field of surface chemical analysis. The chapter addresses the physical basis of the method, the principal design of recent instruments together with modes of operation and options for the presentation of spectra, as well as different approaches for qualitative (including identification of chemical species) and quantitative surface analysis of elements. An application paragraph on surface chemical analysis of nanoparticles by AES or SAM introduces the different measurement approaches and sample preparation strategies applied by analysts. The analysis of nanoparticle ensembles, the so-called selected point analysis where a narrow primary electron beam is centered on an individual nanoparticle, and chemical mapping of individual nanoparticles (or a line scan across) are addressed. Existing literature is reviewed and informative case studies presented. Limitations and pitfalls in the application of AES in surface chemical analysis of nanoparticles are also addressed.
As one of the widely used analytical methods for the analysis of elemental composition of solid matter, energy dispersive X-ray spectroscopy (EDS) has recently gained significant importance regarding its application to the chemical analysis of nanoparticles, especially in conjunction with the use of a scanning electron microscope (SEM) and the use of the transmission operation mode of SEM (STEM-in-SEM). This development was mainly driven by the technological progress with highly sensitive EDS detectors, such that individual nanoparticles can be quickly inspected with EDS at a SEM. Qualitative information on elemental composition with about 10 nm spatial resolution can be achieved complementary to the high-resolution information of the sample surface morphology within the same scanned area as provided by the electron microscope. Representative examples with successful EDS analysis on nanoparticles are presented, but also limitations of the method are described.
This chapter offers observations and considerations concerning black writing inks encountered in writing supports transmitting documentary and literary texts of the late Antiquity and early Middle Ages. It discusses different types of inks, the Methods of their detection and their use in different times and geographical areas.
Subfloors are layered structures, consisting largely of porous building materials, such as screed. They are often suffering damage from tap water leakage, which is a typical problem in buildings, and which has largely contributed to repair costs of almost 3 billion Euro in 2018 alone in Germany. In this context, especially mould plays a role, which is both destroying the structure and posing severe health risks.
To determine the damaging effects of moisture, it is necessary to know the respective processes occurring in building materials, especially to quantify the amount of moisture and its progress in the material. In this study, humidity sensors are used to derive the material moisture experimentally.
Capacitive sensors recording the relative humidity are embedded into the screed and in the insulation materials such as expanded polystyrene, extruded polystyrene, perlite and glass wool. For the application in screed, the sensors need to be shielded against the aggressive alkaline materials. To ensure an appropriate exchange with the environment, a permeable membrane is requested. Different membrane materials have been investigated regarding their robustness and their permeability.
In the first experimental setup, two humidity sensor arrays with seven individual sensors are embedded in homogeneous screed samples. The measured corresponding relative humidity of the screed is converted to the material moisture based on the approach of Hillerborg. In a second experimental setup, a layered structure of a complete subfloor is built in a box of 0.8 m times 0.8 m. The humidity sensors are positioned in the different insulation materials of various thicknesses. By adding water, leakage damage is simulated and its progress and effect is investigated experimentally.
The investigations point at the question if the observed moisture is able to generate damage such as mould. The moisture and corresponding humidity values are discussed. It will be shown that this low-cost hygrometric approach can be used easily for moisture monitoring of screed and insulation materials as well