TY - JOUR A1 - Collings, R. A1 - Rietbrock, Andreas A1 - Lange, Dietrich A1 - Tilmann, F. A1 - Nippress, Stuart A1 - Natawidjaja, D. T1 - Seismic anisotropy in the sumatra subduction zone JF - Journal of geophysical research : Solid earth N2 - An important tool for understanding deformation occurring within a subduction zone is the measurement of seismic anisotropy through observations of shear wave splitting (SWS). In Sumatra, two temporary seismic networks were deployed between December 2007 and February 2009, covering the fore arc between the fore-arc islands to the back arc. We use SKS and local SWS measurements to determine the type, amount, and location of anisotropy. Local SWS measurements from the fore-arc islands exhibit trench-parallel fast directions which can be attributed to shape preferred orientation of cracks/fractures in the overriding sediments. In the Sumatran Fault region, the predominant fast direction is fault/trench parallel, while in the back-arc region it is trench perpendicular. The trench-perpendicular measurements exhibit a positive correlation between delay time and raypath length in the mantle wedge, while the fault-parallel measurements are similar to the fault-parallel fast directions observed for two crustal events at the Sumatran Fault. This suggests that there are two layers of anisotropy: one due to entrained flow within the mantle wedge and a second layer within the overriding crust due to the shear strain caused by the Sumatran Fault. SKS splitting results show a NNW-SSE fast direction with delay times of 0.8-3.0s. The fast directions are approximately parallel to the absolute plate motion of the subducting Indo-Australian Plate. The small delay times exhibited by the local SWS (0.05-0.45s), in combination with the large SKS delay times, suggest that the anisotropy generating the teleseismic SWS is dominated by entrained flow in the asthenosphere below the slab. KW - Sumatra KW - Anisotropy KW - Shear wave splitting KW - Subduction zone KW - Mantle rheology Y1 - 2013 U6 - https://doi.org/10.1002/jgrb.50157 SN - 2169-9313 SN - 2169-9356 VL - 118 IS - 10 SP - 5372 EP - 5390 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Hoang, Hoa T. A1 - Haubitz, Toni A1 - Kumke, Michael Uwe T1 - Photophysics of "Floppy" Dyadsas Potential Biomembrane Probes JF - Journal of fluorescence N2 - In the study a dyad (C6 probe), constructed of two dyes with highly different hydrophobicities, was investigated by steady-state and time-resolved spectroscopic techniques in chloroform, methanol, and in phospholipid vesicles, respectively. The dyad was built on two dyes: the lipophilic benzo[a]pyrene (BaP) and the hydrophilic sulforhodamine B (SRB). The dyes were linked via a short, but flexible alkyl chain (six C-atoms). Based on their spectroscopic properties, BaP and SRB showed a very efficient non-radiative resonance energy transfer in solution. Incorporation into a lipid bilayer limited the relative flexibility (degree of freedom) between donor and acceptor and was used for the investigation of fundamental photophysical aspects (especially of FRET) as well as to elucidate the potential of the dyad to probe the interface of vesicles (or cells). The location of the two dyes in vesicles and their respective accessibility for interactions with dye-specific antibodies was investigated. Based on the alteration of the anisotropy, on the rotational correlation time as well as on the diffusion coefficient the incorporation of the C6 probe into the vesicles was evaluated. Especially the limitation in the relative movements of the two dyes was considered and used to differentiate between potential parameters, that influence the energy transfer in the dyad. Transient absorption spectroscopy (TAS) and pulsed-interleave single molecule fluorescence experiments were performed to better understand the intramolecular interactions in the dyad. Finally, in a showcase for a biosensing application of the dyads, the binding of an SRB-specific antibody was investigated when the dyad was incorporated in vesicles. KW - Forster resonance energy transfer(FRET) KW - Antibody binding KW - Vesicles KW - Anisotropy KW - Fluorescence correlation KW - Single molecule fluorescence KW - Transient absorption KW - Pulsed interleaved excitation Y1 - 2018 U6 - https://doi.org/10.1007/s10895-018-2286-4 SN - 1053-0509 SN - 1573-4994 VL - 28 IS - 5 SP - 1225 EP - 1237 PB - Springer CY - New York ER - TY - JOUR A1 - Rheinwalt, Aljoscha A1 - Boers, Niklas A1 - Marwan, Norbert A1 - Kurths, Jürgen A1 - Hoffmann, Peter A1 - Gerstengarbe, Friedrich-Wilhelm A1 - Werner, Peter T1 - Non-linear time series analysis of precipitation events using regional climate networks for Germany JF - Climate dynamics : observational, theoretical and computational research on the climate system N2 - Synchronous occurrences of heavy rainfall events and the study of their relation in time and space are of large socio-economical relevance, for instance for the agricultural and insurance sectors, but also for the general well-being of the population. In this study, the spatial synchronization structure is analyzed as a regional climate network constructed from precipitation event series. The similarity between event series is determined by the number of synchronous occurrences. We propose a novel standardization of this number that results in synchronization scores which are not biased by the number of events in the respective time series. Additionally, we introduce a new version of the network measure directionality that measures the spatial directionality of weighted links by also taking account of the effects of the spatial embedding of the network. This measure provides an estimate of heavy precipitation isochrones by pointing out directions along which rainfall events synchronize. We propose a climatological interpretation of this measure in terms of propagating fronts or event traces and confirm it for Germany by comparing our results to known atmospheric circulation patterns. KW - Rainfall KW - Complex networks KW - Precipitation events KW - Anisotropy KW - Dominant link directions KW - Isochrones KW - Event synchronization Y1 - 2016 U6 - https://doi.org/10.1007/s00382-015-2632-z SN - 0930-7575 SN - 1432-0894 VL - 46 SP - 1065 EP - 1074 PB - Springer CY - New York ER - TY - JOUR A1 - Sevostianov, Igor A1 - Bruno, Giovanni T1 - Maxwell scheme for internal stresses in multiphase composites JF - Mechanics of Materials N2 - The paper focuses on the reformulation of classic Maxwell's (1873) homogenization method for calculation of the residual stresses in matrix composites. For this goal, we equate the far fields produced by a set of inhomogeneities subjected to known eigenstrains and by a fictitious domain with unknown eigenstrain. The effect of interaction between the inhomogeneities is reduced to the calculation of the additional field acting on an inhomogeneity due to the eigenstrains in its neighbors. An explicit formula for residual stresses is derived for the general case of a multiphase composite. The method is illustrated by several examples. The results are compared with available experimental data as well as with predictions provided by the non-interaction approximation (Eshelby solution). It is shown that accounting for interaction can explain many experimentally observed phenomena and is required for adequate quantitative analytical modeling of the residual stresses in matrix composites. KW - Residual stress KW - Multiphase composites KW - Interaction KW - Micromechanical schemes KW - Anisotropy Y1 - 2018 U6 - https://doi.org/10.1016/j.mechmat.2018.12.005 SN - 0167-6636 SN - 1872-7743 VL - 129 SP - 320 EP - 331 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Schuster, Valerian A1 - Rybacki, Erik A1 - Bonnelye, Audrey A1 - Herrmann, Johannes A1 - Schleicher, Anja Maria A1 - Dresen, Georg T1 - Experimental deformation of opalinus clay at elevated temperature and pressure conditions BT - Mechanical properties and the influence of rock fabric JF - Rock mechanics and rock engineering N2 - The mechanical behavior of the sandy facies of Opalinus Clay (OPA) was investigated in 42 triaxial tests performed on dry samples at unconsolidated, undrained conditions at confining pressures (p(c)) of 50-100 MPa, temperatures (T) between 25 and 200 degrees C and strain rates (epsilon) (over dot ) of 1 x-10(-3)-5 x-10(-6) -s(-1). Using a Paterson-type deformation apparatus, samples oriented at 0 degrees, 45 degrees and 90 degrees to bedding were deformed up to about 15% axial strain. Additionally, the influence of water content, drainage condition and pre-consolidation was investigated at fixed p(c)-T conditions, using dry and re-saturated samples. Deformed samples display brittle to semi-brittle deformation behavior, characterized by cataclastic flow in quartz-rich sandy layers and granular flow in phyllosilicate-rich layers. Samples loaded parallel to bedding are less compliant compared to the other loading directions. With the exception of samples deformed 45 degrees and 90 degrees to bedding at p(c) = 100 MPa, strain is localized in discrete shear zones. Compressive strength (sigma(max)) increases with increasing pc, resulting in an internal friction coefficient of approximate to 0.31 for samples deformed at 45 degrees and 90 degrees to bedding, and approximate to 0.44 for samples deformed parallel to bedding. In contrast, pre-consolidation, drainage condition, T and epsilon(over dot )do not significantly affect deformation behavior of dried samples. However, sigma(max) and Young's modulus (E) decrease substantially with increasing water saturation. Compared to the clay-rich shaly facies of OPA, sandy facies specimens display higher strength sigma(max) and Young's modulus E at similar deformation conditions. Strength and Young's modulus of samples deformed 90 degrees and 45 degrees to bedding are close to the iso-stress Reuss bound, suggesting a strong influence of weak clay-rich layers on the deformation behavior. KW - Clay rock KW - Sandy facies of Opalinus Clay KW - Triaxial deformation experiments KW - Microstructural deformation mechanisms KW - Pressure-temperature and strain rate-dependent mechanical behaviour KW - Anisotropy Y1 - 2021 U6 - https://doi.org/10.1007/s00603-021-02474-3 SN - 0723-2632 SN - 1434-453X VL - 54 SP - 4009 EP - 4039 PB - Springer CY - Wien ER - TY - JOUR A1 - Eisold, Ursula A1 - Sellrie, Frank A1 - Schenk, Jörg A. A1 - Lenz, Christine A1 - Stöcklein, Walter F. M. A1 - Kumke, Michael Uwe T1 - Bright or dark immune complexes of anti-TAMRA antibodies for adapted fluorescence-based bioanalysis JF - Analytical & bioanalytical chemistry N2 - Fluorescence labels, for example fluorescein or rhodamin derivatives, are widely used in bioanalysis applications including lateral-flow assays, PCR, and fluorescence microscopy. Depending on the layout of the particular application, fluorescence quenching or enhancement may be desired as the detection principle. Especially for multiplexed applications or high-brightness requirements, a tunable fluorescence probe can be beneficial. The alterations in the photophysics of rhodamine derivatives upon binding to two different anti-TAMRA antibodies were investigated by absorption and fluorescence-spectroscopy techniques, especially determining the fluorescence decay time and steady-state and time-resolved fluorescence anisotropy. Two monoclonal anti-TAMRA antibodies were generated by the hybridoma technique. Although surface-plasmon-resonance measurements clearly proved the high affinity of both antibodies towards 5-TAMRA, the observed effects on the fluorescence of rhodamine derivatives were very different. Depending on the anti-TAMRA antibody either a strong fluorescence quenching (G71-DC7) or a distinct fluorescence enhancement (G71-BE11) upon formation of the immune complex was observed. Additional rhodamine derivatives were used to gain further information on the binding interaction. The data reveal that such haptens as 5-TAMRA could generate different paratopes with equal binding affinities but different binding interactions, which provide the opportunity to adapt bioanalysis methods including immunoassays for optimized detection principles for the same hapten depending on the specific requirements. KW - mAb KW - Fluorescence KW - Anisotropy KW - Exciplex KW - Energy-transfer probe Y1 - 2015 U6 - https://doi.org/10.1007/s00216-015-8538-0 SN - 1618-2642 SN - 1618-2650 VL - 407 IS - 12 SP - 3313 EP - 3323 PB - Springer CY - Heidelberg ER -