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Organisationseinheit der BAM
Errichtet aus Glas und Beton prägen heute unzählige Sakralbauten der 1950er- und 60er-Jahre unsere Stadtbilder. Nicht selten sind in diesen Kirchen erhebliche Schäden an den Betonglasfenstern zu verzeichnen. Diese fachgemäß zu erhalten, erfordert spezielles technisches und denkmalpflegerisches Know-how. An der Entwicklung geeigneter Instandsetzungsstrategien arbeitet derzeit ein interdisziplinäres Projektteam.
Termite gut flagellates are colonized by host-specific lineages of ectosymbiotic and endosymbiotic bacteria. Previous studies have shown that flagellates of the genus Trichonympha may harbour more than one type of symbiont. Using a comprehensive approach that combined cloning of SSU rRNA genes with fluorescence in situ hybridization and electron microscopy, we investigated the phylogeny and subcellular locations of the symbionts in a variety of Trichonympha species from different termites. The flagellates in Trichonympha Cluster I were the only species associated with 'Endomicrobia', which were located in the posterior part of the cell, confirming previous results. Trichonympha species of Cluster II from the termite genus Incisitermes (family Kalotermitidae) lacked 'Endomicrobia' and were associated with endosymbiotic Actinobacteria, which is highly unusual. The endosymbionts, for which we suggest the name 'Candidatus Ancillula trichonymphae', represent a novel, deep-branching lineage in the Micrococcineae that consists exclusively of clones from termite guts. They preferentially colonized the anterior part of the flagellate host and were highly abundant in all species of Trichonympha Cluster II except Trichonympha globulosa. Here, they were outnumbered by a Desulfovibrio species associated with the cytoplasmic lamellae at the anterior cell pole. Such symbionts are present in both Trichonympha clusters, but not in all species. Unlike the intracellular location reported for the Desulfovibrio symbionts of Trichonympha agilis (Cluster I), the Desulfovibrio symbionts of T. globulosa (Cluster II) were situated in deep invaginations of the plasma membrane that were clearly connected to the exterior of the host cell.
The paper gives an overview on safe life and damage tolerance methods applied to railway axles. It describes failure scenarios due to fatigue crack initiation and propagation. Besides common aspects of design, specific features such as corrosion and impact damage from flying ballast are discussed which may reduce the fatigue strength of axles during service. Potential effects of non-metallic inclusions from the steel manufacturing process are addressed in the context of the very high number of loading cycles railway axles are designed for. With respect to damage tolerance general lines of fracture mechanics residual lifetime analyses are introduced. More specific discussion is provided on aspects such as the threshold value of fatigue crack propagation and reliability aspects of non-destructive inspection.
This paper presents, the investigation of tunable components based on LTCC technology, implementing ferroelectric tunable thick-film dielectric. The tunable loaded line phase shifters are fabricated with metal-insulator-metal (MIM) varactors to demonstrate the capabilities of this method for packaging of the tunable components. The MIM varactors consist of one tunable dielectric paste layer that is printed between two silver layers. The tunable ferroelectric paste is optimized for LTCC sintering temperature around 850°C. The phase shifters are fabricated in two different process. They were achieved a figure of merit of 24°/dB (phase shift 192°) at 3 GHz and 18°/dB (phase shift 98°) at 4.4 GHz by using seven unit cells that each unit cell consisting of two MIM varactors.
The analysis of pollen chemical composition is important to many fields, including agriculture, plant physiology, ecology, allergology, and climate studies. Here, the potential of a combination of different spectroscopic and spectrometric methods regarding the characterization of small biochemical differences between pollen samples was evaluated using multivariate statistical approaches. Pollen samples, collected from three populations of the grass Poa alpina, were analyzed using Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, surface enhanced Raman scattering (SERS), and matrix assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS). The variation in the sample set can be described in a hierarchical framework comprising three populations of the same grass species and four different growth conditions of the parent plants for each of the populations. Therefore, the data set can work here as a model system to evaluate the classification and characterization ability of the different spectroscopic and spectrometric methods. ANOVA Simultaneous Component Analysis (ASCA) was applied to achieve a separation of different sources of variance in the complex sample set. Since the chosen methods and sample preparations probe different parts and/or molecular constituents of the pollen grains, complementary information about the chemical composition of the pollen can be obtained. By using consensus principal component analysis (CPCA), data from the different methods are linked together. This enables an investigation of the underlying global information, since complementary chemical data are combined. The molecular information from four spectroscopies was combined with phenotypical information gathered from the parent plants, thereby helping to potentially link pollen chemistry to other biotic and abiotic parameters.
In this paper, we investigate the evaporation mass flow originating from spills of gas-oline. Large spills of gasoline may form during partial or complete roof sinkings or inthe case of perforations at various deck fittings at external floating roof tanks usedfor the storage. Additionally, spills may form in the retention area in the case of leak-ages at pipes or at the hull. The aim is to predict the order of magnitude of real-scaleevaporation mass flow. The determined evaporation mass flows will be used in arelated project as input values for subsequent dispersion modeling in the vicinity ofthe tanks. This is relevant for questions of fire and explosion protection as well as forenvironmental protection aspects in tank farms or refineries, which use externalfloating roof tanks. The measurements presented in this paper were compared withpredictions by empirical models and investigations of evaporations from small floorspills, round-bottom flask, or from Petri dishes published in the literature. The maingoal of this paper is to test the applicability of empirical models to provide reasonableevaporation mass flows as input for CFD dispersion simulations.
MALDI time-of-flight mass spectrometry (MALDI-TOF MS) has become a widely used tool for the classification of biological samples. The complex chemical composition of pollen grains leads to highly specific, fingerprint-like mass spectra, with respect to the pollen species. Beyond the species-specific composition, the variances in pollen chemistry can be hierarchically structured, including the level of different populations, of environmental conditions or different genotypes. We demonstrate here the sensitivity of MALDI-TOF MS regarding the adaption of the chemical composition of three Poaceae (grass) pollen for different populations of parent plants by analyzing the mass spectra with partial least squares discriminant analysis (PLS-DA) and principal component analysis (PCA). Thereby, variances in species, population and specific growth conditions of the plants were observed simultaneously. In particular, the chemical pattern revealed by the MALDI spectra enabled discrimination of the different populations of one species. Specifically, the role of environmental changes and their effect on the pollen chemistry of three different grass species is discussed. Analysis of the Group formation within the respective populations showed a varying influence of plant genotype on the classification, depending on the species, and permits conclusions regarding the respective rigidity or plasticity towards environmental changes.
1. Fourier transform infrar ed (FTIR) spectroscopy enables chemical analysis of pollen samples for plant phenotyping to stud y plant–environment interactions, such as influence of climate change or pathogens. However, current approach, such as microspectrosc opy and attenuated total refle ction spectrosco py, doe s not allow fo r high-throughput protocols. This st udy at hand suggests a new sp ectroscopic method for high-throughp ut characterization of pollen.
2. Samples were measured as thin films of pollen fragments using a Bruker FTIR spe ctrometer with a high-throughput eXTension (HTS-XT) unit employing 384-well plates. In total, 146 pollen samples, belonging to 31 different pollen species of Fagaceae and Betulaceae and collected during three consecutive years (2012–2014) at locations in Croatia, Germany and Norway, were analysed. Critical steps in the sample preparation and measurement, such as variabilities between technical replicates, between microplates and between spectrometers, were studied.
3. Measurement variations due to sample preparation, microplate holders and instrumentation were low, and thus allowed differentiation of samples with respect to phylogeny and biogeography. The spectral variability for a ran ge of Fagales spec ies (Fagus, Quercus, Betula, Corylus, Alnus and Ostrya) showed high-species-specific differences in pollen’s chemical composition due to eithe r location or year. Statistically significant inter-annual and locational differences in the pollen spectra indicate that pollen chemical composition has high phenotypic plasticity and is influenced by local climate conditions. The variations in composition are connected to lipids, proteins, carbohydrates and sporopollenins that play crucial ro les in cold and desiccation tolerance, protection against UV radiation and as material and energy reserves.
4. The results of this study demonstrate the value of high-throughput FTIR approach for the systematic collection of data on ecosystems. The novel FTIR approach offers fast, reliable and economical screening of large number of samples by semi-automated methodology. The high-throughput approach could provide crucial understanding on plant–climate interactions with respect to biochemical variation within genera, species and populations.