TY - JOUR A1 - Palkowski, Carsten A1 - Schwarzenberg, S. A1 - Simo, Anne T1 - Seasonal cooling performance of air conditioners: The importance of independent test procedures used for MEPS and labels N2 - Minimum energy performance standards and labels are commonly used tools to reduce the household energy use thus mitigating greenhouse gas emissions. However, the technical foundation for minimum energy performance standards and labels are test procedures for rating and testing of appliances. To de- termine the seasonal cooling performance of air conditioners, the current test standards require fixing of the compressor speed of the units to achieve steady-state conditions; this way of operation, how- ever, differs from real-life use. To make the seasonal cooling performance testing better reflect the real use conditions, this study proposes a compensation method which can be conducted independently from manufacturer data and still allows modulation of the tested units. Our results show that the tested units behave differently under part-load conditions, which results in a lower energy efficiency rating for some of the tested devices. KW - Air conditioner KW - Independent test method KW - Real use behavior KW - Seasonal energy efficiency ratio KW - Minimum energy performance standards KW - Energy label PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-485813 DO - https://doi.org/10.1016/j.ijrefrig.2019.05.021 SN - 0140-7007 VL - 104 SP - 417 EP - 425 PB - Elsevier AN - OPUS4-48581 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Steger, Simon A1 - Oesterle, D. A1 - Bretz, S. A1 - Frenzel, L. A1 - Stege, H. A1 - Winkelmeyer, I. A1 - Hahn, Oliver A1 - Geiger, G. T1 - Kandinsky’s fragile art: a multidisciplinary investigation of four early reverse glass paintings (1911–1914) by Wassily Kandinsky N2 - This work highlights the rediscovery of the technique of reverse glass painting by the artists of the “Blaue Reiter” collective in the early 20th-century and focusses particularly on the role of Wassily Kandinsky (1866–1944). Kandinsky created more than 70 reverse paintings on glass and showed several of them in exhibitions together with paintings on canvas and cardboard, implying a coequal importance of these techniques. Four of his early (1911–1914) reverse glass paintings (Auferstehung, Allerheiligen II, Rudern, Apokalyptischer Reiter II) were selected for investigation and their iconography, painting techniques and painting materials were examined. Two paintings were executed on so-called cathedral glass, revealing a “hammered surface”, whereas Kandinsky used a corrugated glass panel for Rudern. A multi-analytical, non-invasive approach [X-ray fluorescence (XRF), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), VIS spectroscopy (VIS), Raman spectroscopy] was taken to identify the pigments and classify the binding media. The results reveal a broad palette of materials. Several pigments like lead white, zinc white, Strontium yellow, Prussian blue, viridian, cadmium yellow, ultramarine blue, cinnabar and carbon black were found in most of the four paintings. The use of the rare synthetic organic pigments PR60 and PB52 is discussed. In two works of art, cadmium carbonate is associated with cadmium yellow. The identification of aluminium foil along with tin foils in Rudern indicates an early use of this material for reverse glass paintings. KW - Reverse glass painting KW - Non-invasive analysis KW - Raman spectroscopy KW - DRIFTS PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-480075 DO - https://doi.org/10.1186/s40494-019-0268-8 VL - 7 IS - 27 SP - 1 EP - 17 PB - Springer AN - OPUS4-48007 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Blaeß, Carsten A1 - Müller, Ralf A1 - Poologasundarampilai, G. A1 - Brauer, D. S. T1 - Sintering and concomitant crystallization of bioactive glasses N2 - The sintering of bioactive glasses allows for the preparation of complex structures, such as three‐dimensional porous scaffolds. Such 3D constructs are particularly interesting for clinical applications of bioactive glasses in bone regeneration, as the scaffolds can act as a guide for in‐growing bone cells, allowing for good Integration with existing and newly formed tissue while the scaffold slowly degrades. Owing to the pronounced tendency of many bioactive glasses to crystallize upon heat treatment, 3D scaffolds have not been much exploited commercially. Here, we investigate the influence of crystallization on the sintering behavior of several bioactive glasses. In a series of mixed‐alkali glasses an increased CaO/alkali metal oxide Ratio improved sintering compared to Bioglass 45S5, where dense sintering was inhibited. Addition of small amounts of calcium fluoride helped to keep melting and sintering temperatures low. Unlike glass 13‐93, these new glasses crystallized during sintering but this did not prevent densification. Variation in bioactive glass particle size allowed for fine‐tuning the microporosity resulting from the sintering process. KW - Bioactive glass KW - Crystallization KW - Scaffolds KW - Sintering PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-485458 DO - https://doi.org/10.1111/ijag.13477 SN - 2041-1286 VL - 10 IS - 4 SP - 449 EP - 462 PB - Wiley AN - OPUS4-48545 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Staude, Andreas A1 - Scholtz, G. A1 - Dunlop, J. A. T1 - Trilobite compound eyes with crystalline cones and rhabdoms show mandibulate affinities N2 - Most knowledge about the structure, function, and evolution of early compound eyes is based on investigations in trilobites. However, these studies dealt mainly with the cuticular lenses and little was known about internal anatomy. Only recently some data on crystalline cones and retinula cells were reported for a Cambrian trilobite species. Here, we describe internal eye structures of two other trilobite genera. The Ordovician Asaphus sp. reveals preserved crystalline cones situated underneath the cuticular lenses. The same is true for the Devonian species Archegonus (Waribole) warsteinensis, which in addition shows the fine structure of the rhabdom in the retinula cells. These results suggest that an apposition eye with a crystalline cone is ancestral for Trilobita. The overall similarity of trilobite eyes to those of myriapods, crustaceans, and hexapods corroborates views of a phylogenetic position of trilobites in the stem lineage of Mandibulata. KW - Coputed tomography KW - Crystalline cones PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-483889 DO - https://doi.org/10.1038/s41467-019-10459-8 SN - 2041-1723 VL - 10 SP - 2503, 1 EP - 7 PB - Nature AN - OPUS4-48388 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Belenguer, A. A1 - Michalchuk, Adam A1 - Lampronti, G A1 - Sanders, J T1 - Understanding the unexpected effect of frequency on the kinetics of a covalent reaction under ball-milling conditions N2 - We here explore how ball-mill-grinding frequency affects the kinetics of a disulfide exchange reaction. Our kinetic data show that the reaction progress is similar at all the frequencies studied (15–30 Hz), including a significant induction time before the nucleation and growth process starts. This indicates that to start the reaction an initial energy accumulation is necessary. Other than mixing, the energy supplied by the mechanical treatment has two effects: (i) reducing the crystal size and (ii) creating defects in the structure. The crystal-breaking process is likely to be dominant at first becoming less important later in the process when the energy supplied is stored at the molecular level as local crystal defects. This accumulation is taken here to be the rate-determining step. We suggest that the local defects accumulate preferentially at or near the crystal surface. Since the total area increases exponentially when the crystal size is reduced by the crystal-breaking process, this can further explain the exponential dependence of the onset time on the milling frequency. KW - Mechanochemistry KW - Kinetics KW - Diffraction PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-483361 DO - https://doi.org/10.3762/bjoc.15.120 SN - 2195-951X VL - 15 SP - 1226 EP - 1235 PB - Beilstein-Institut zur Förderung der Chemischen Wissenschaften CY - Frankfurt, M. AN - OPUS4-48336 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Treiling, S. A1 - Wang, Cui A1 - Förster, C. A1 - Reichenauer, F. A1 - Kalmbach, J. A1 - Boden, P. A1 - Harris, J. P. A1 - Carrella, L. M. A1 - Rentschler, E. A1 - Resch-Genger, Ute A1 - Reber, C. A1 - Seitz, M. A1 - Gerhards, M. A1 - Heinze, K. T1 - Luminescence and Light-Driven Energy and Electron Transfer from an Exceptionally Long-Lived Excited State of a Non-Innocent Chromium(III) Complex N2 - Photoactive metal complexes employing Earth‐abundant metal ions are a key to sustainable photophysical and photochemical applications. We exploit the effects of an inversion center and ligand non‐innocence to tune the luminescence and photochemistry of the excited state of the [CrN6] chromophore [Cr(tpe)2]3+ with close to octahedral symmetry (tpe=1,1,1‐tris(pyrid‐2‐yl)ethane). [Cr(tpe)2]3+ exhibits the longest luminescence lifetime (τ=4500 μs) reported up to date for a molecular polypyridyl chromium(III) complex together with a very high luminescence quantum yield of Φ=8.2 % at room temperature in fluid solution. Furthermore, the tpe ligands in [Cr(tpe)2]3+ are redox non‐innocent, leading to reversible reductive chemistry. The excited state redox potential and lifetime of [Cr(tpe)2]3+ surpass those of the classical photosensitizer [Ru(bpy)3]2+ (bpy=2,2′‐bipyridine) enabling energy transfer (to oxygen) and photoredox processes (with azulene and tri(n‐butyl)amine). KW - Quantum yield KW - Cr(III) complex KW - Longst luminescence lifetime KW - Electron transfer PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-494870 DO - https://doi.org/10.1002/anie.201909325 VL - 58 SP - 2 EP - 13 PB - Wiley-VCH AN - OPUS4-49487 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Baer, Wolfram T1 - Chunky graphite in ferritic spheroidal graphite cast iron: Formation, prevention, characterization, impact on properties – An overview N2 - Ferritic spheroidal graphite cast iron (SGI) materials have a remarkable technical poten-tial and economic impact in modern industry. These features are closely related to the question of how the cast materials can be produced without structural defects and graphite degenerations such as for example chunky graphite. Although the chunky graphite degeneration superficially seems to be well known, its metallurgical background is still controversially discussed, appropriate field-tested non-destructive tools for its quantification in castings are lacking and the knowledge on its impact on material properties is fairly limited. Addressing this status, the article is providing a current overview on the subject. Existing theories on formation and growth mechanisms of chunky graphite are briefly reviewed. Furthermore, from a metallurgical point of view, causes for the appearance of chunky graphite as well as preventive measures are concisely summarized. Particular attention is paid to the morphology of chunky graphite and how it can be characterized by destructive and non-destructive techniques. Special emphasis was laid on providing a comprehensive overview on the impact of chunky graphite on strength, ductility, fatigue limit, fatigue crack growth rate as well as fracture tough-ness of ferritic SGI materials based on experimental data. Moreover, conclusions for the assessment of castings affected by chunky graphite are drawn. KW - Characterization KW - Ferritic spheroidal graphite cast iron KW - Chunky graphite KW - Properties KW - Formation KW - Prevention PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-499972 DO - https://doi.org/10.1007/s40962-019-00363-8 SN - 1939-5981 SN - 2163-3193 VL - 14 IS - 2 SP - 454 EP - 488 PB - Springer Verlag AN - OPUS4-49997 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sentker, K. A1 - Yildirim, Arda A1 - Lippmann, M. A1 - Zantop, A. W. A1 - Bertram, F. A1 - Hofmann, T. A1 - Seeck, O. H. A1 - Kityk, A. A1 - Mazza, M. G. A1 - Schönhals, Andreas A1 - Huber, P. T1 - Self-assembly of liquid crystals in nanoporous solids for adaptive photonic metamaterials N2 - Nanoporous media exhibit structures significantly smaller than the wavelengths of visible light and can thus act as photonic metamaterials. Their optical functionality is not determined by the properties of the base materials, but rather by tailored, multiscale structures, in terms of precise pore shape, geometry, and orientation. Embedding liquid crystals in pore space provides additional opportunities to control light–matter interactions at the single-pore, meta-atomic scale. Here, we present temperature-dependent 3D reciprocal space mapping using synchrotron-based X-ray diffraction in combination with high-Resolution birefringence experiments on disk-like mesogens (HAT6) imbibed in self-ordered arrays of parallel cylindrical pores 17 to 160 nm across in monolithic anodic aluminium oxide (AAO). In agreement with Monte Carlo computer simulations we observe a remarkably rich self-assembly behaviour, unknown from the bulk state. It encompasses transitions between the isotropic liquid state and discotic stacking in linear columns as well as circular concentric ring formation perpendicular and parallel to the pore axis. These textural transitions underpin an optical birefringence functionality, tuneable in magnitude and in sign from positive to negative via pore size, pore surface-grafting and temperature. Our study demonstrates that the advent of large-scale, self-organised nanoporosity in monolithic solids along with confinement-controllable phase behaviour of liquid-crystalline matter at the single-pore scale provides a reliable and accessible tool to design materials with adjustable optical anisotropy, and thus offers versatile pathways to finetune polarisation-dependent light propagation speeds in materials. Such a tailorability is at the core of the emerging field of transformative optics, allowing, e.g., adjustable light absorbers and extremely thin metalenses. KW - Discotic Liquid Crystals PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-499601 DO - https://doi.org/10.1039/c9nr07143a SP - 1 EP - 14 PB - RSC Royal Society of Chemistry AN - OPUS4-49960 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hicke, Konstantin A1 - Eisermann, René A1 - Chruscicki, Sebastian T1 - Enhanced Distributed Fiber Optic Vibration Sensing and Simultaneous Temperature Gradient Sensing Using Traditional C-OTDR and Structured Fiber with Scattering Dots N2 - We present results demonstrating several beneficial effects on distributed fiber optic vibration sensing (DVS) functionality and performance resulting from utilizing standard single mode optical fiber (SMF) with femtosecond laser-inscribed equally-spaced simple scattering dots. This modification is particularly useful when using traditional single-wavelength amplitude-based coherent optical time domain reflectometry (C-OTDR) as sensing method. Local sensitivity is increased in quasi-distributed interferometric sensing zones which are formed by the fiber segments between subsequent pairs of the scattering dots. The otherwise nonlinear transfer function is overwritten with that of an ordinary two-beam interferometer. This linearizes the phase response to monotonous temperature variations. Furthermore, sensitivity fading is mitigated and the demodulation of low-frequency signals is enabled. The modification also allows for the quantitative determination of local temperature gradients directly from the C-OTDR intensity traces. The dots’ reflectivities and thus the induced attenuation can be tuned via the inscription process parameters. Our approach is a simple, robust and cost-effective way to gain these sensing improvements without the need for more sophisticated interrogator technology or more complex fiber structuring, e.g., based on ultra-weak FBG arrays. Our claims are substantiated by experimental evidence. KW - Fiber optic sensors KW - Distributed vibration sensing KW - DVS KW - Distributed temperature gradient sensing KW - DTGS KW - C-OTDR KW - Phase-sensitive KW - OTDR KW - Fiber structuring KW - Fs-inscription PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-499281 DO - https://doi.org/10.3390/s19194114 VL - 19 IS - 19 SP - 4114 PB - MDPI CY - Basel, Switzerland AN - OPUS4-49928 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Woydt, Mathias T1 - Sub-stoichiometric oxides for wear resistance N2 - In the present work it was shown that the tribologcal profiles of special model oxides under dry unidirectional sliding have shown, that sub-oxides have a contribution to the tribological behavior of carbides and cermets, when they are tribo-oxidatively formed, because their tribological profiles as monolithic materials are homologous in part or totally, or compete with hardmetals or cermets, depending from the operating conditions regarded. KW - Sub-oxide KW - Friction KW - Wear KW - Carbide KW - Hardmetal PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-498154 DO - https://doi.org/10.1016/j.wear.2019.203104 SN - 0043-1648 N1 - Eine identische Version zu diesem Artikel wurde publiziert unter: Wear 438-439 (2019) 102735, https://doi.org/10.1016/j.wear.2019.01.066 - An identical version to this article was published under: Wear 438-439 (2019) 102735, https://doi.org/10.1016/j.wear.2019.01.066 VL - 440-441 SP - 203104-1 EP - 203104-7 PB - Elsevier CY - Amsterdam AN - OPUS4-49815 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stajanca, Pavol A1 - Hicke, Konstantin A1 - Krebber, Katerina T1 - Distributed Fiberoptic Sensor for Simultaneous Humidity and Temperature Monitoring Based on Polyimide-Coated Optical Fibers N2 - Along temperature, humidity is one of the principal environmental factors that plays an important role in various application areas. Presented work investigates possibility of distributed fiberoptic humidity monitoring based on humidity-induced strain measurement in polyimide (PI)-coated optical fibers. Characterization of relative humidity (RH) and temperature response of four different commercial PI- and one acrylate-coated fiber was performed using optical backscattering reflectometry (OBR). The study addresses issues of temperature-humidity cross sensitivity, fiber response stability, repeatability, and the influence of annealing. Acrylate-coated fiber exhibited rather unfavorable nonlinear RH response with strong temperature dependence, which makes it unsuitable for humidity sensing applications. On the other hand, humidity response of PI-coated fibers showed good linearity with fiber sensitivity slightly decreasing at rising temperatures. In the tested range, temperature sensitivity of the fibers remained humidity independent. Thermal annealing was shown to considerably improve and stabilize fiber RH response. Based on performed analysis, a 20 m sensor using the optimal PI-coated fibers was proposed and constructed. The sensor uses dual sensing fiber configuration for mutual decoupling and simultaneous measurement of temperature and RH variations. Using OBR, distributed dual temperature-RH monitoring with cm spatial resolution was demonstrated for the first time. KW - Distributed humidity sensing KW - Fiberoptic sensors KW - Polyimide-coated optical fibers KW - Optical frequency-domain reflectometry KW - Dual sensing PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-498871 DO - https://doi.org/10.3390/s19235279 VL - 19 IS - 23 SP - 5279 PB - MDPI AN - OPUS4-49887 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nöller, Renate A1 - Danielewski, A. A1 - Giel, R. A1 - Overgaauw, E. A1 - Hahn, Oliver T1 - Material analysis of Aztec codices in Berlin. Assignment of small fragments compiled as cutouts on one plate in Humboldt’s “Atlas pittoresque du voyage” N2 - The collection Manuscripta Americana in Berlin consists of fragmented codices acquired by Alexander von Humboldt in Mexico. Some of these Humboldt Codices are published as hieroglyphic writings of the Aztecs in “Vues des Cordilleres et Monuments des Peuples indigènes de l’Amerique”. Starting from a special compilation of seven fragments on plate 36 in the “Atlas”, we investigated the corresponding original fragments using material analysis in order to clarify their historical relations. The analyses were carried out with X-ray fluorescence analysis, VIS spectroscopy, and infrared spectroscopy in diffuse reflection and revealed typical indigenous colors like cochineal, indigo, and organic yellows (e.g. mangrove and zacatlaxcalli). Four fragments under investigation show exactly the same material and thus must once have belonged together in one compendium. An additional manuscript from Mizquiahuala also shown on plate 36 can be matched to another one that is not published in the “Atlas”. KW - Manuscripts KW - Alexander von Humboldt KW - Non-destructiv testing KW - Colourants KW - Writing materials PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-498971 DO - https://doi.org/10.1080/20548923.2019.1682816 SN - 2054-8923 SP - 1 EP - 14 PB - Routledge, Taylor & Francis Group CY - London AN - OPUS4-49897 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kockert, M. A1 - Mitdank, R. A1 - Zykov, A. A1 - Kowarik, Stefan A1 - Fischer, F. T1 - Absolute Seebeck coefficient of thin platinum films N2 - The influence of size effects on the thermoelectric properties of thin platinum films is investigated and compared to the bulk. Structural properties, like the film thickness and the grain size, are varied. We correlate the electron mean free path with the temperature dependence of the electrical conductivity and the absolute Seebeck coefficient SPt of platinum. A measurement platform was developed as a standardized method to determine SPt and show that SPt,film is reduced compared to SPt,bulk. Boundary and surface scattering reduce the thermodiffusion and the phonon drag contribution to SPt,film by nearly the same factor. We discuss in detail on behalf of a model, which describes the temperature dependence of the absolute Seebeck coefficient, the influence of size effects of electron-phonon and phonon-phonon interaction on SPt. KW - Thin magnetic films PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-499007 DO - https://doi.org/10.1063/1.5101028 SN - 0021-8979 VL - 126 SP - 105106 PB - AIP AN - OPUS4-49900 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Büchele, Dominique A1 - Chao, Madlen A1 - Ostermann, Markus A1 - Leenen, M. A1 - Bald, Ilko T1 - Multivariate chemometrics as a key tool for prediction of K and Fe in a diverse German agricultural soil-set using EDXRF N2 - Within the framework of precision agriculture, the determination of various soil properties is moving into focus, especially the demand for sensors suitable for in-situ measurements. Energy-dispersive X-ray fluorescence (EDXRF) can be a powerful tool for this purpose. In this study a huge diverse soil set (n = 598) from 12 different study sites in Germany was analysed with EDXRF. First, a principal component analysis (PCA) was performed to identify possible similarities among the sample set. Clustering was observed within the four texture classes clay, loam, silt and sand, as clay samples contain high and sandy soils low iron mass fractions. Furthermore, the potential of uni- and multivariate data evaluation with partial least squares regression (PLSR) was assessed for accurate Determination of nutrients in German agricultural samples using two calibration sample sets. Potassium and iron were chosen for testing the performance of both models. Prediction of these nutrients in 598 German soil samples with EDXRF was more accurate using PLSR which is confirmed by a better overall averaged deviation and PLSR should therefore be preferred. KW - XRF KW - Chemometrics KW - Soil KW - Agriculture KW - Multivariate PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-498671 DO - https://doi.org/10.1038/s41598-019-53426-5 VL - 9 SP - 17588 PB - Nature AN - OPUS4-49867 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liu, H. A1 - Song, W. A1 - Gröninger, Delia A1 - Zhang, L. A1 - Lu, Y. A1 - Chan, K. S. A1 - Zhou, Z. A1 - Rurack, Knut A1 - Shen, Z. T1 - Real-time monitoring of newly acidified organelles during autophagy enabled by reaction-based BODIPY dyes N2 - Real-time monitoring of newly acidified organelles during autophagy in living cells is highly desirable for a better understanding of intracellular degradative processes. Herein, we describe a reaction-based boron dipyrromethene (BODIPY) dye containing strongly electron-withdrawing diethyl 2-cyanoacrylate groups at the α-positions. The probe exhibits intense red fluorescence in acidic organelles or the acidified cytosol while negligible fluorescence in other regions of the cell. The underlying mechanism is a nucleophilic reaction at the central meso-carbon of the indacene core, resulting in the loss of π-conjugation entailed by dramatic spectroscopic changes of more than 200 nm between its colorless, non-fluorescent leuco-BODIPY form and its red and brightly emitting form. The reversible transformation between red fluorescent BODIPY and leuco-BODIPY along with negligible cytotoxicity qualifies such dyes for rapid and direct intracellular lysosome imaging and cytosolic acidosis detection simultaneously without any washing step, enabling the real-time monitoring of newly acidified organelles during autophagy. KW - Autophagy KW - BODIPY KW - Fluorescence KW - Lysosome KW - Real-time imaging PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-498358 UR - https://www.nature.com/articles/s42003-019-0682-1 DO - https://doi.org/10.1038/s42003-019-0682-1 SN - 23993642 VL - 2 SP - 442 PB - Nature Research CY - London AN - OPUS4-49835 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Meyer, A. A1 - Weidner, Steffen A1 - Kricheldorf, H. T1 - Stereocomplexation of cyclic polylactides with each other and with linear poly(L-lactide)s N2 - Two kinds of cyclic poly(D- and L-lactide)s were synthesized, namely CI labeled samples mainly consisting of even-numbered cycles with low dispersity and CII, CIII or CIV-labeled ones consisting of equal amounts of even and odd-numbered cycles with high dispersity and igher molecular weights (Mw up to 300 000). Furthermore, linear poly L-lactide)s were prepared by initiation with ethanol and in both series the molecular weight was varied. The formation of stereocomplexes from cyclic poly(D-lactide)s and all kinds of poly L-lactide)s was performed in dichloromethane/toluene mixtures. The stereocomplexes crystallized from the reaction mixture were characterized in the virgin state and after annealing at 205 °C. Stereocomplexes free of stereohomopolymers with crystallinities up to 80% were obtained from all experiments in yields ranging from 60 to 80%. Despite the high annealing temperature (maintained for 1 h), little transesterification was observed and the crystallinity slightly increased. KW - Polylactide KW - MALDI-TOF MS KW - Stereocomplex KW - Cyclic PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-496693 DO - https://doi.org/10.1039/c9py01236b VL - 10 SP - 6191 EP - 6199 PB - Royal Society for Chemistry AN - OPUS4-49669 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schütz, R. A1 - Maragh, J. A1 - Weaver, J. A1 - Rabin, Ira A1 - Masic, A. T1 - The Temple Scroll: Reconstructing an ancient manufacturing practice N2 - The miraculously preserved 2000-year-old Dead Sea Scrolls, ancient texts of invaluable historical significance, were discovered in the mid-20th century in the caves of the Judean desert. The texts were mainly written on parchment and exhibit vast diversity in their states of preservation. One particular scroll, the 8-m-long Temple Scroll is especially notable because of its exceptional thinness and bright ivory color. The parchment has a layered structure, consisting of a collagenous base material and an atypical inorganic overlayer. We analyzed the chemistry of the inorganic layer using x-ray and Raman spectroscopies and discovered a variety of evaporitic sulfate salts. This points toward a unique ancient production technology in which the parchment was modified through the addition of the inorganic layer as a writing surface. Furthermore, understanding the properties of these minerals is particularly critical for the development of suitable conservation methods for the preservation of these invaluable historical documents. KW - Temple Scroll KW - Dead Sea Scrolls PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-495314 DO - https://doi.org/10.1126/sciadv.aaw7494 VL - 5 IS - 9 SP - 1 EP - 9 PB - AAAS AN - OPUS4-49531 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Haustein, T. A1 - Busweiler, Sabine A1 - Haustein, V. A1 - von Laar, C. A1 - Plarre, Rüdiger T1 - Laboratory breeding of Korynetes caeruleus (Coleoptera: Cleridae) for the biological of Anobium punctatum) (Coleoptera, Ptinidae) N2 - Larvae and adults of Korynetes caeruleus (de Geer 1775) (Coleoptera: Cleridae) were collected from old churches and reared in the laboratory on Anobium punctatum (de Geer 1774) (Coleoptera: Ptinidae). Breeding success of K. caeruleus was low, but basic parameters of this species’ developmental cycle were identifi ed. At 21°C and 75% relative humidity and a fourmonth cold period at 4°C, the development of K. caeruleus from egg to adult appearance lasted 2 years. The pupal stage may be reached and completed after one and a half years. Feeding on larvae of A. punctatum by larvae of K. caeruleus was observed and consisted of a combination of sucking haemolymph and consuming body parts. The sickle-like mandibles of larvae of K. caeruleus penetrate the cuticle of prey larvae; this is followed by pumping and sucking body movements. Adult beetles of A. punctatum were not attacked by K. caeruleus larvae. Feeding behaviour of adult K. caeruleus was not investigated. KW - Cultural heritage KW - Coleoptera KW - Korynetes caeruleus KW - Cleridae KW - Ptinidae KW - Anobium punctatum KW - Biological pest control KW - Life history data KW - Laboratory breeding KW - Wood protection PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-494999 DO - https://doi.org/10.14411/eje.2019.038 SN - 1802-8829 VL - 116 SP - 362 EP - 371 PB - České Budějovice AN - OPUS4-49499 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Descalzo, Ana B. A1 - Ashokkumar, Pichandi A1 - Shen, Z. A1 - Rurack, Knut T1 - On the Aggregation Behaviour and Spectroscopic Properties of Alkylated and Annelated BoronDipyrromethene (BODIPY) Dyes in Aqueous Solution N2 - The tendency of boron-dipyrromethene (BODIPY) dyes to associate in water is well known, and usually a cause for inferior fluorescence properties. Synthetic efforts to chemically improve BODIPYs’ water solubility and minimize this problem have been numerous in the past. However, a deeper understanding of the phenomena responsible for fluorescence quenching is still required. Commonly, the spectroscopic behaviour in aqueous media has been attributed to aggregate or excimer formation, with such works often centring on a single BODIPY family. Herein, we provide an integrating discussion including very diverse types of BODIPY dyes. Our studies revealed that even subtle structural changes can distinctly affect the association behaviour of the fluorophores in water, involving different photophysical processes. The palette of behaviour found ranges from unperturbed emission, to the formation of H or J aggregates and excimers, to the involvement of tightly bound, preformed excimers. These results are a first step to a more generalized understanding of spectroscopic properties vs. structure, facilitating future molecular design of BODIPYs, especially as probes for biological applications. KW - Aggregates KW - BODIPY KW - Excimers KW - Fluorescence KW - Photophysics PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-497771 DO - https://doi.org/10.1002/cptc.201900235 SN - 2367-0932 VL - 4 IS - 2 SP - 120 EP - 131 PB - WILEY-VCH CY - Weinheim AN - OPUS4-49777 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Henning, L. M. A1 - Simon, U. A1 - Gurlo, A. A1 - Smales, Glen Jacob A1 - Bekheet, M. F. T1 - Grafting and stabilization of ordered mesoporous silica COK-12 with graphene oxide for enhanced removal of methylene blue N2 - Large-pore ordered mesoporous silica (OMS) COK-12, analogous to the well-known SBA-15, but synthesized in a more environmentally friendly way and exhibiting a shorter plate-like structure, was grafted with different amounts of graphene oxide (GO) for the first time in an inexpensive and rapid process, that was successfully upscaled. Samples were examined with nitrogen sorption analysis, SAXS, Raman spectroscopy, XPS, and zeta potential analysis. Adsorption experiments with the cationic dye methylene blue (MB) were conducted on the grafted materials and on pure COK-12, taking into account the influence of initial dye concentration (30–600 mg L-1), adsorbent dosage (0.2–14 g L-1), contact time (0.3–300 min), solution pH (4 10), and influence of salts and temperature (0–1 M NaCl, 80 C) to simulate industrial dye effluent. The adsorption process was found to be represented best by the Langmuir isotherm model, i.e., adsorption is a monolayer process. The calculated maximum Adsorption capacities were found to be 20.2 and 197.5 mg g-1 at dosages of 5 and 0.5 g L-1 for pure COK-12 and COK-12 grafted with 50 wt% GO, respectively, at pH 5.65 and MB concentration of 100 mg L-1. Adsorption kinetics were found to follow the pseudo-second order model, i.e., chemisorption is the rate controlling step. The adsorption performances could be well preserved at simulated dye effluent. Desorption was found to be most effective with hydrochloric acid. The COK-12 grafted with GO presented in this work shows superior adsorption properties in comparison to other grafted OMS materials. In addition, grafting with GO remarkably improved the stability of COK-12 in aqueous solution. KW - COK-12 KW - Mesoporous Silica KW - Graphene Oxide KW - Large-pore PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-497788 UR - https://pubs.rsc.org/en/content/articlehtml/2019/ra/c9ra05541j DO - https://doi.org/10.1039/c9ra05541j VL - 9 IS - 62 SP - 36271 EP - 36284 PB - Royal Society of Chemistry AN - OPUS4-49778 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -