TY - JOUR A1 - Chen, Jialin A1 - Su, Yingna A1 - Liu, Rui A1 - Kliem, Bernhard A1 - Zhang, Qingmin A1 - Ji, Haisheng A1 - Liu, Tie T1 - Partial eruption, confinement, and twist buildup and release of a double-decker filament JF - The astrophysical journal : an international review of spectroscopy and astronomical physics. N2 - We investigate the failed partial eruption of a filament system in NOAA AR 12104 on 2014 July 5, using multiwavelength EUV, magnetogram, and H alpha observations, as well as magnetic field modeling. The filament system consists of two almost co-spatial segments with different end points, both resembling a C shape. Following an ejection and a precursor flare related to flux cancellation, only the upper segment rises and then displays a prominent twisted structure, while rolling over toward its footpoints. The lower segment remains undisturbed, indicating that the system possesses a double-decker structure. The erupted segment ends up with a reverse-C shape, with material draining toward its footpoints, while losing its twist. Using the flux rope insertion method, we construct a model of the source region that qualitatively reproduces key elements of the observed evolution. At the eruption onset, the model consists of a flux rope atop a flux bundle with negligible twist, which is consistent with the observational interpretation that the filament possesses a double-decker structure. The flux rope reaches the critical height of the torus instability during its initial relaxation, while the lower flux bundle remains in stable equilibrium. The eruption terminates when the flux rope reaches a dome-shaped quasi-separatrix layer that is reminiscent of a magnetic fan surface, although no magnetic null is found. The flux rope is destroyed by reconnection with the confining overlying flux above the dome, transferring its twist in the process. Y1 - 2021 U6 - https://doi.org/10.3847/1538-4357/ac2ba1 SN - 0004-637X SN - 1538-4357 VL - 923 IS - 2 PB - Institute of Physics Publ. CY - London ER - TY - JOUR A1 - Silverii, Francesca A1 - Maccaferri, Francesco A1 - Richter, Gudrun A1 - Gonzalez Cansado, Borja A1 - Wang, Rongjiang A1 - Hainzl, Sebastian A1 - Dahm, Torsten T1 - Poroelastic model in a vertically sealed gas storage BT - a case study from cyclic injection/production in a carbonate aquifer JF - Geophysical journal international / the Royal Astronomical Society, the Deutsche Geophysikalische Gesellschaft and the European Geophysical Society N2 - Natural gas can be temporarily stored in a variety of underground facilities, such as depleted gas and oil fields, natural aquifers and caverns in salt rocks. Being extensively monitored during operations, these systems provide a favourable opportunity to investigate how pressure varies in time and space and possibly induces/triggers earthquakes on nearby faults. Elaborate and detailed numerical modelling techniques are often applied to study gas reservoirs. Here we show the possibilities and discuss the limitations of a flexible and easily formulated tool that can be straightforwardly applied to simulate temporal pore-pressure variations and study the relation with recorded microseismic events. We use the software POEL (POroELastic diffusion and deformation) which computes the poroelastic response to fluid injection/extraction in a horizontally layered poroelastic structure. We further develop its application to address the presence of vertical impermeable faults bounding the reservoir and of multiple injection/extraction sources. Exploiting available information on the reservoir geometry and physical parameters, and records of injection/extraction rates for a gas reservoir in southern Europe, we perform an extensive parametric study considering different model configurations. Comparing modelled spatiotemporal pore-pressure variations with in situ measurements, we show that the inclusion of vertical impermeable faults provides an improvement in reproducing the observations and results in pore-pressure accumulation near the faults and in a variation of the temporal pore-pressure diffusion pattern. To study the relation between gas storage activity and recorded local microseismicity, we applied different seismicity models based on the estimated porepressure distribution. This analysis helps to understand the spatial distribution of seismicity and its temporal modulation. The results show that the observed microseismicity could be partly linked to the storage activity, but the contribution of tectonic background seismicity cannot be excluded. KW - Permeability and porosity KW - Gas and hydrate systems KW - Europe KW - Induced KW - seismicity Y1 - 2021 U6 - https://doi.org/10.1093/gji/ggab268 SN - 0956-540X SN - 1365-246X VL - 227 IS - 2 SP - 1322 EP - 1338 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Demske, Ulrike T1 - Variation Across Newspapers in Early Modern German BT - Degrees of Syntactic Complexity JF - Journal of Historical Syntax (Special issue: Cross-disciplinary approaches to linguistic variation in Early Modern West Germanic) N2 - The administrative language used in imperial and city chanceries illustrates formal language use in the Early Modern period, as most evident in its syntactic complexity. Since administrative language was considered prestigious by the literate people of the time, the syntactic features in question are increasingly found in other text types as well (Lötscher 1995, Schwitalla 2002). The present paper investigates early newspapers published in the seventeenth and eighteenth centuries to evalute their degree of syntactic complexity and hence the extent of formal language used. Contrary to common belief (Admoni 1980, von Polenz 2013), it will be shown that early newspapers do not allow a uniform assessment in terms of their syntactic complexity, when they emerge as a new genre in the seventeenth century: some news segments display a fairly simple syntax, whereas others are of high syntactic complexity. By the end of the eighteenth century, the growing conventionalization of the new genre as well as the impact of standardization processes render newspapers much more balanced in terms of syntactic complexity. Unlike previous work on the syntactic complexity of newspaper language, the measurement of syntactic complexity takes into account not only sentence length and the relationship between independent and dependent clauses, but also the placement of adverbial clauses in relation to their associated clause. KW - variation KW - syntactic complexity KW - adverbial clauses KW - register Y1 - 2022 U6 - https://doi.org/10.18148/hs/2022.v6i13-18.136 SN - 2163-6001 VL - 6 SP - 1 EP - 36 PB - University of Konstanz CY - Konstanz ER - TY - JOUR A1 - Büyükakpınar, Pınar A1 - Cesca, Simone A1 - Hainzl, Sebastian A1 - Jamalreyhani, Mohammadreza A1 - Heimann, Sebastian A1 - Dahm, Torsten T1 - Reservoir-triggered earthquakes around the Atatürk Dam (Southeastern Turkey) JF - Frontiers in Earth Science N2 - Reservoir-triggered seismicity has been observed near dams during construction, impoundment, and cyclic filling in many parts of the earth. In Turkey, the number of dams has increased substantially over the last decade, with Ataturk Dam being the largest dam in Turkey with a total water capacity of 48.7 billion m(3). After the construction of the dam, the monitoring network has improved. Considering earthquakes above the long-term completeness magnitude of M-C = 3.5, the local seismicity rate has substantially increased after the filling of the reservoir. Recently, two damaging earthquakes of M-w 5.5 and M-w 5.1 occurred in the town of Samsat near the Ataturk Reservoir in 2017 and 2018, respectively. In this study, we analyze the spatio-temporal evolution of seismicity and its source properties in relation to the temporal water-level variations and the stresses resulting from surface loading and pore-pressure diffusion. We find that water-level and seismicity rate are anti-correlated, which is explained by the stabilization effect of the gravitational induced stress imposed by water loading on the local faults. On the other hand, we find that the overall effective stress in the seismogenic zone increased over decades due to pore-pressure diffusion, explaining the enhanced background seismicity during recent years. Additionally, we observe a progressive decrease of the Gutenberg-Richter b-value. Our results indicate that the stressing rate finally focused on the region where the two damaging earthquakes occurred in 2017 and 2018. KW - reservoir-triggered seismicity KW - earthquake source parameters KW - stress-change KW - seismic hazard KW - Ataturk Dam Y1 - 2021 U6 - https://doi.org/10.3389/feart.2021.663385 SN - 2296-6463 VL - 9 PB - Frontiers Media CY - Lausanne ER - TY - JOUR A1 - Gostkowska-Lekner, Natalia A1 - Kojda, Sandrino Danny A1 - Hoffmann, Jan-Ekkehard A1 - May, Manfred A1 - Huber, Patrick A1 - Habicht, Klaus A1 - Hofmann, Tommy T1 - Synthesis of organic-inorganic hybrids based on the conjugated polymer P3HT and mesoporous silicon JF - Microporous and mesoporous materials : zeolites, clays, carbons and related materials N2 - Organic-inorganic hybrids are a class of functional materials that combine favorable properties of their constituents to achieve an overall improved performance for a wide range of applications. This article presents the synthesis route for P3HT-porous silicon hybrids for thermoelectric applications. The conjugated polymer P3HT is incorporated into the porous silicon matrix by means of melt infiltration. Gravimetry, sorption isotherms and energy dispersive X-ray spectroscopy (EDX) mapping indicate that the organic molecules occupy more than 50% of the void space in the inorganic host. We demonstrate that subsequent diffusion-based doping of the confined polymer in a FeCl3 solution increases the electrical conductivity of the hybrid by five orders of magnitude compared to the empty porous silicon host. KW - Mesoporous silicon KW - P3HT KW - Organic-inorganic hybrid KW - Melt infiltration Y1 - 2022 U6 - https://doi.org/10.1016/j.micromeso.2022.112155 SN - 1387-1811 SN - 1873-3093 VL - 343 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Bartsch, Annett A1 - Pointner, Georg A1 - Nitze, Ingmar A1 - Efimova, Aleksandra A1 - Jakober, Dan A1 - Ley, Sarah A1 - Högström, Elin A1 - Grosse, Guido A1 - Schweitzer, Peter T1 - Expanding infrastructure and growing anthropogenic impacts along Arctic coasts JF - Environmental research letters : ERL / Institute of Physics N2 - The accelerating climatic changes and new infrastructure development across the Arctic require more robust risk and environmental assessment, but thus far there is no consistent record of human impact. We provide a first panarctic satellite-based record of expanding infrastructure and anthropogenic impacts along all permafrost affected coasts (100 km buffer, approximate to 6.2 Mio km(2)), named the Sentinel-1/2 derived Arctic Coastal Human Impact (SACHI) dataset. The completeness and thematic content goes beyond traditional satellite based approaches as well as other publicly accessible data sources. Three classes are considered: linear transport infrastructure (roads and railways), buildings, and other impacted area. C-band synthetic aperture radar and multi-spectral information (2016-2020) is exploited within a machine learning framework (gradient boosting machines and deep learning) and combined for retrieval with 10 m nominal resolution. In total, an area of 1243 km(2) constitutes human-built infrastructure as of 2016-2020. Depending on region, SACHI contains 8%-48% more information (human presence) than in OpenStreetMap. 221 (78%) more settlements are identified than in a recently published dataset for this region. 47% is not covered in a global night-time light dataset from 2016. At least 15% (180 km(2)) correspond to new or increased detectable human impact since 2000 according to a Landsat-based normalized difference vegetation index trend comparison within the analysis extent. Most of the expanded presence occurred in Russia, but also some in Canada and US. 31% and 5% of impacted area associated predominantly with oil/gas and mining industry respectively has appeared after 2000. 55% of the identified human impacted area will be shifting to above 0 C-circle ground temperature at two meter depth by 2050 if current permafrost warming trends continue at the pace of the last two decades, highlighting the critical importance to better understand how much and where Arctic infrastructure may become threatened by permafrost thaw. KW - Arctic KW - permafrost KW - settlements KW - infrastructure KW - remote sensing KW - machine KW - learning KW - Sentinel Y1 - 2021 U6 - https://doi.org/10.1088/1748-9326/ac3176 SN - 1748-9326 VL - 16 IS - 11 PB - IOP Publ. Ltd. CY - Bristol ER - TY - JOUR A1 - Hofmann, Tommy A1 - Kojda, Sandrino Danny A1 - Haseeb, Haider A1 - Wallacher, Dirk A1 - Sobolev, Oleg A1 - Habicht, Klaus T1 - Phonons in highly-crystalline mesoporous silicon: the absence of phonon-softening upon structuring silicon on sub-10 nanometer length scales JF - Microporous and mesoporous materials : the official journal of the International Zeolite Association N2 - This article presents inelastic thermal neutron scattering experiments probing the phonon dispersion in mesoporous silicon with pores 8 nm across. Scattering studies reveal the energy-momentum relation for transverse and longitudinal phonons along the high symmetry directions , and in the Brillouin zone. The dispersion up to phonon energies of 35 meV unambiguously proves that the phonon group velocities in highly-crystalline silicon are not modified by nanostructuring down to sub-10 nanometer length scales. On these length scales, there is apparently no effect of structuring on the elastic moduli of mesoporous silicon. No evidence can be found for phonon-softening in topologically complex, geometrically disordered mesoporous silicon putting it in contrast to silicon nanotubes and nanoribbons. KW - Mesoporous silicon KW - Inelastic neutron scattering KW - Phonon dispersion KW - Phonon-softening KW - Elasticity KW - Thermoelectric material Y1 - 2021 U6 - https://doi.org/10.1016/j.micromeso.2020.110814 SN - 1387-1811 SN - 1873-3093 VL - 312 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Keller, Lena A1 - Cortina, Kai S. A1 - Müller, Katharina A1 - Miller, Kevin F. T1 - Noticing and weighing alternatives in the reflection of regular classroom teaching: evidence of expertise using mobile eye-tracking JF - Instructional science : an international journal of learning and cognition N2 - Instructional videos are widely used to study teachers' professional vision. A new technological development in video research is mobile eye-tracking (MET). It has the potential to provide fine-grained insights into teachers' professional vision in action, but has yet been scarcely employed. We addressed this research gap by using MET video feedback to examine how expert and novice teachers differed in their noticing and weighing of alternative teaching strategies. Expert and novice teachers' lessons were recorded with MET devices. Then, they commented on what they observe while watching their own teaching videos. Using a mixed methods approach, we found that expert and novice teachers did not differ in the number of classroom events they noticed and alternative teaching strategies they mentioned. However, novice teachers were more critical of their own teaching than expert teachers, particularly when they considered alternative teaching strategies. Practical implications for the field of teacher education are discussed. KW - Mobile eye-tracking KW - Expertise KW - Teacher training KW - Think-aloud KW - Professional vision Y1 - 2022 U6 - https://doi.org/10.1007/s11251-021-09570-5 SN - 0020-4277 SN - 1573-1952 VL - 50 IS - 2 SP - 251 EP - 272 PB - Springer Science + Business Media B.V. CY - Dordrecht [u.a.] ER - TY - JOUR A1 - Roeser, Patricia A1 - Drager, Nadine A1 - Brykala, Dariusz A1 - Ott, Florian A1 - Pinkerneil, Sylvia A1 - Gierszewski, Piotr A1 - Lindemann, Christin A1 - Plessen, Birgit A1 - Brademann, Brian A1 - Kaszubski, Michal A1 - Fojutowski, Michal A1 - Schwab, Markus J. A1 - Slowinski, Michal A1 - Blaszkiewicz, Miroslaw A1 - Brauer, Achim T1 - Advances in understanding calcite varve formation: new insights from a dual lake monitoring approach in the southern Baltic lowlands JF - Boreas : an international journal of quaternary research N2 - We revise the conceptual model of calcite varves and present, for the first time, a dual lake monitoring study in two alkaline lakes providing new insights into the seasonal sedimentation processes forming these varves. The study lakes, Tiefer See in NE Germany and Czechowskie in N Poland, have distinct morphology and bathymetry, and therefore, they are ideal to decipher local effects on seasonal deposition. The monitoring setup in both lakes is largely identical and includes instrumental observation of (i) meteorological parameters, (ii) chemical profiling of the lake water column including water sampling, and (iii) sediment trapping at both bi-weekly and monthly intervals. We then compare our monitoring data with varve micro-facies in the sediment record. One main finding is that calcite varves form complex laminae triplets rather than simple couplets as commonly thought. Sedimentation of varve sub-layers in both lakes is largely dependent on the lake mixing dynamics and results from the same seasonality, commencing with diatom blooms in spring turning into a pulse of calcite precipitation in summer and terminating with a re-suspension layer in autumn and winter, composed of calcite patches, plant fragments and benthic diatoms. Despite the common seasonal cycle, the share of each of these depositional phases in the total annual sediment yield is different between the lakes. In Lake Tiefer See calcite sedimentation has the highest yields, whereas in Lake Czechowskie, the so far underestimated re-suspension sub-layer dominates the sediment accumulation. Even in undisturbed varved sediments, re-suspended material becomes integrated in the sediment fabric and makes up an important share of calcite varves. Thus, while the biogeochemical lake cycle defines the varves' autochthonous components and micro-facies, the physical setting plays an important role in determining the varve sub-layers' proportion. Y1 - 2021 U6 - https://doi.org/10.1111/bor.12506 SN - 0300-9483 SN - 1502-3885 VL - 50 IS - 2 SP - 419 EP - 440 PB - Wiley-Blackwell CY - Oxford [u.a.] ER - TY - JOUR A1 - Korovila, Ioanna A1 - Hoehn, Annika A1 - Jung, Tobias A1 - Grune, Tilman A1 - Ott, Christiane T1 - Reduced liver autophagy in high-fat diet induced liver steatosis in New Zealand obese mice JF - Antioxidants : open access journal N2 - Non-alcoholic fatty liver disease (NAFLD), as a consequence of overnutrition caused by high-calorie diets, results in obesity and disturbed lipid homeostasis leading to hepatic lipid droplet formation. Lipid droplets can impair hepatocellular function; therefore, it is of utmost importance to degrade these cellular structures. This requires the normal function of the autophagic-lysosomal system and the ubiquitin-proteasomal system. We demonstrated in NZO mice, a polygenic model of obesity, which were compared to C57BL/6J (B6) mice, that a high-fat diet leads to obesity and accumulation of lipid droplets in the liver. This was accompanied by a loss of autophagy efficiency whereas the activity of lysosomal proteases and the 20S proteasome remained unaffected. The disturbance of cellular protein homeostasis was further demonstrated by the accumulation of 3-nitrotyrosine and 4-hydroxynonenal modified proteins, which are normally prone to degradation. Therefore, we conclude that fat accumulation in the liver due to a high-fat diet is associated with a failure of autophagy and leads to the disturbance of proteostasis. This might further contribute to lipid droplet stabilization and accumulation. KW - proteostasis KW - protein modification KW - 4-HNE KW - proteasome KW - lipid droplets Y1 - 2021 U6 - https://doi.org/10.3390/antiox10040501 SN - 2076-3921 VL - 10 IS - 4 PB - MDPI CY - Basel ER -