Review

Understanding the reactivity of (semiconductor) pigments provides vital information on how to improve conservation strategies for works of art to avoid rapid degradation of the pigments. This study focuses on the photoactivity of minium (Pb$_3$O$_4$), a semiconductor pigment that gives rise to strong discoloration phenomena upon exposure to various environmental conditions. [...]

The absorptionof lightgivesapigmentits colourand its reasonforbeing,but it alsocreatesexcitedstates,that is,new moleculeswithanenergyexcessthat can be dissipatedthroughdegradationpathways.Photodegradationprocessesprovokelong-term,cumulativeand irre-versiblecolourchanges(fading,darkening,blanching) of whichthepredictionand preventionare challengingtasks.Ofall the environ-mentalrisksthat affectheritagematerials,light exposureis the onlyone that cannotbe controlledwithoutany impacton the optimaldis-playof the exhibit.Light-inducedalterationsare not onlyassociatedwiththe pigmentitselfbut also withits interactionswithsupport/binderand,in turn,are furthercomplicatedby the natureof the environ-mentalconditions.Inthis Minireviewwe investigatehowchemistry,encompassingmulti-scaleanalyticalinvestigationsof worksof art,computationalmodellingand physicaland chemicalstudiescontrib-utes to improveour predictionof artworkappearancebeforedegra-dationand to establisheffectivepreventiveconservationstrategies..

Ultraschnelle Elektronenmikroskope und Röntgenstrahlungsquellen basieren auf beschleunigten und präzise geformten Elektronenpaketen. Unsere Gruppe am DESY konnte kürzlich zeigen, wie mit sehr hochfrequenter Strahlung im Terahertzbereich kompakte Bauelemente für die Elektronenbeschleunigung realisiert und mit leichter Abwandlung auch zur zeitlichen und räumlichen Pulsformung sowie Pulscharakterisierung verwendet werden können..

In order to build a positron source for the ILC, a high energy density irradiation is needed to test the used materials. At the MAMI linear accelerator such a radiation can be provided at different electron energies. [...]

Knowledge about the mechanisms involved in the structural development of solid materials at the atomic level is essential for designing rational synthesis protocols for these compounds, which may be used to improve desired technical properties, such as light emission, conductivity, magnetism, porosity or particle size, and may allow the tailored design of solid materials to generate the aforementioned properties. Recent technological advancements have allowed the combination of synchrotron-based in situ X-ray diffraction (XRD) with in situ optical spectroscopy techniques, providing researchers with remarkable opportunities to directly investigate structural changes during synthesis reactions [...]

The International Axion Observatory (IAXO) is a proposed 4th-generation axion helioscope with the primary physics research goal to search for solar axions via their Primakoff conversion into photons of 1 – 10 keV energies in a strong magnetic field. IAXO will achieve a sensitivity to the axion-photon coupling gaγ down to a few ×10−12 GeV−1 for a wide range of axion masses up to ∼ 0.25 eV. [...]

Diamond-cobalt composites are used for cutting tools. Residual stress after manufacturecan reduce the lifetime of such composite cutting tools and, hence, the stress state needs to be wellunderstood. [...]

Manufacturing diamond-cobalt composites by sintering results in residual stresses due tothe mismatch of thermal expansion coefficients mainly. To understand the influence ofmanufacturing process parameters on residual stresses of sintered diamond-cobalt compositessamples are produced by different process parameters. [...]

In this research work, Ti/TiAlN multilayers of various designs were deposited onsubstrates pretreated by nitriding and etching procedures. The influence of the multilayer design onresidual stress depth profiles was systematically analyzed for multilayers with different Titaniuminterlayer thicknesses. [...]