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- ItemSediment budgeting of short‐term backfilling processes: The erosional collapse of a Carolingian canal construction(New York, NY [u.a.] : Wiley, 2020) Schmidt, Johannes; Werther, Lukas; Rabiger‐Völlmer, Johannes; Herzig, Franz; Schneider, Birgit; Werban, Ulrike; Dietrich, Peter; Berg, Stefanie; Linzen, Sven; Ettel, Peter; Zielhofer, ChristophSediment budgeting concepts serve as quantification tools to decipher the erosion and accumulation processes within a catchment and help to understand these relocation processes through time. While sediment budgets are widely used in geomorphological catchment-based studies, such quantification approaches are rarely applied in geoarchaeological studies. The case of Charlemagne's summit canal (also known as Fossa Carolina) and its erosional collapse provides an example for which we can use this geomorphological concept and understand the abandonment of the Carolingian construction site. The Fossa Carolina is one of the largest hydro-engineering projects in Medieval Europe. It is situated in Southern Franconia (48.9876°N, 10.9267°E; Bavaria, southern Germany) between the Altmühl and Swabian Rezat rivers. It should have bridged the Central European watershed and connected the Rhine–Main and Danube river systems. According to our dendrochronological analyses and historical sources, the excavation and construction of the Carolingian canal took place in AD 792 and 793. Contemporary written sources describe an intense backfill of excavated sediment in autumn AD 793. This short-term erosion event has been proposed as the principal reason for the collapse and abandonment of the hydro-engineering project. We use subsurface data (drillings, archaeological excavations, and direct-push sensing) and geospatial data (a LiDAR digital terrain model (DTM), a pre-modern DTM, and a 3D model of the Fossa Carolina] for the identification and sediment budgeting of the backfills. Dendrochronological findings and radiocarbon ages of macro remains within the backfills give clear evidence for the erosional collapse of the canal project during or directly after the construction period. Moreover, our quantification approach allows the detection of the major sedimentary collapse zone. The exceedance of the manpower tipping point may have caused the abandonment of the entire construction site. The spatial distribution of the dendrochronological results indicates a north–south direction of the early medieval construction progress.
- ItemEemian landscape response to climatic shifts and evidence for northerly Neanderthal occupation at a palaeolake margin in northern Germany(New York, NY [u.a.] : Wiley, 2021-9-14) Hein, Michael; Urban, Brigitte; Tanner, David Colin; Buness, Anton Hermann; Tucci, Mario; Hoelzmann, Philipp; Dietel, Sabine; Kaniecki, Marie; Schultz, Jonathan; Kasper, Thomas; Suchodoletz, Hans von; Schwalb, Antje; Weiss, Marcel; Lauer, TobiasThe prevailing view suggests that the Eemian interglacial on the European Plain was characterized by largely negligible geomorphic activity beyond the coastal areas. However, systematic geomorphological studies are sparse. Here we present a detailed reconstruction of Eemian to Early Weichselian landscape evolution in the vicinity of a small fingerlake on the northern margin of the Salzwedel Palaeolake in Lower Saxony (Germany). We apply a combination of seismics, sediment coring, pollen analysis and luminescence dating on a complex sequence of colluvial, paludal and lacustrine sediments. Results suggest two pronounced phases of geomorphic activity, directly before the onset and at the end of the Eemian period, with an intermediate period of pronounced landscape stability. The dynamic phases were largely driven by incomplete vegetation cover, but likely accentuated by fluvial incision in the neighbouring Elbe Valley. Furthermore, we discovered Neanderthal occupation at the lakeshore during Eemian pollen zone (PZ) E IV, which is chronologically in line with other known Eemian sites of central Europe. Our highly-resolved spatio-temporal data substantially contribute to the understanding of climate-induced geomorphic processes throughout and directly after the last interglacial period. It helps unraveling the landscape dynamics between the coastal areas to the north and the loess belt to the south.
- ItemLimited life cycle andcost assessment for the bioconversion of lignin‐derived aromatics into adipic acid(New York, NY [u.a.] : Wiley, 2020) van Duuren, Jozef B.J.H.; de Wild, Paul J.; Starck, Sören; Bradtmöller, Christian; Selzer, Mirjam; Mehlmann, Kerstin; Schneider, Roland; Kohlstedt, Michael; Poblete‐Castr, Ignacio; Stolzenberger, Jessica; Barton, Nadja; Fritz, Michel; Scholl, Stephan; Venus, Joachim; Wittmann, ChristophLignin is an abundant and heterogeneous waste byproduct of the cellulosic industry, which has the potential of being transformed into valuable biochemicals via microbial fermentation. In this study, we applied a fast-pyrolysis process using softwood lignin resulting in a two-phase bio-oil containing monomeric and oligomeric aromatics without syringol. We demonstrated that an additional hydrodeoxygenation step within the process leads to an enhanced thermochemical conversion of guaiacol into catechol and phenol. After steam bath distillation, Pseudomonas putida KT2440-BN6 achieved a percent yield of cis, cis-muconic acid of up to 95 mol% from catechol derived from the aqueous phase. We next established a downstream process for purifying cis, cis-muconic acid (39.9 g/L) produced in a 42.5 L fermenter using glucose and benzoate as carbon substrates. On the basis of the obtained values for each unit operation of the empirical processes, we next performed a limited life cycle and cost analysis of an integrated biotechnological and chemical process for producing adipic acid and then compared it with the conventional petrochemical route. The simulated scenarios estimate that by attaining a mixture of catechol, phenol, cresol, and guaiacol (1:0.34:0.18:0, mol ratio), a titer of 62.5 (g/L) cis, cis-muconic acid in the bioreactor, and a controlled cooling of pyrolysis gases to concentrate monomeric aromatics in the aqueous phase, the bio-based route results in a reduction of CO2-eq emission by 58% and energy demand by 23% with a contribution margin for the aqueous phase of up to 88.05 euro/ton. We conclude that the bio-based production of adipic acid from softwood lignins brings environmental benefits over the petrochemical procedure and is cost-effective at an industrial scale. Further research is essential to achieve the proposed cis, cis-muconic acid yield from true lignin-derived aromatics using whole-cell biocatalysts. © 2020 Wiley Periodicals, Inc.
- ItemHighly linear fundamental up-converter in InP DHBT technology for W-band applications(New York, NY [u.a.] : Wiley, 2020) Hossain, Maruf; Stoppel, Dimitri; Boppel, Sebastian; Heinrich, Wolfgang; Krozer, ViktorA fundamental up-converter with high linearity is presented, realized as full Gilbert cell (GC) mixer using a 800 nm transferred substrate (TS) InP-DHBT technology. The LO input of the Gilbert cell conducts from 75 to 100 GHz and requires 5 dBm of input power. The GC attains a single sideband (SSB) conversion gain of 10 ± 1 dB within the frequency from 82 to 95 GHz with a saturated output power of -1 dBm at 86 GHz and >5 dB conversion gain between 75 and 100 GHz. The up-converter exhibits 25 GHz of IF bandwidth. The DC power consumption is only 51 mW. © 2020 The Authors. Microwave and Optical Technology Letters published by Wiley Periodicals, Inc.
- ItemAntioxidant and hydrophilic poly(lactic acid) fibers obtained through their modification with amines and ferulic acid(New York, NY [u.a.] : Wiley, 2017) Wojciechowska, Dorota; Herczyńska, Lucyna; Simon, Frank; Puchalski, Michał; Stawski, DawidThe ferulic acid (FA) is a natural antioxidant, abundantly present in plants, which acts as the plant's immune system. In order to take advantage of its properties, a method has been developed, which combines antioxidant FA with bio-based biodegradable poly(lactic acid) fibers and biocompatible hydrophilic polyallylamine, enabling the production of versatile base material that could be used for active anti-inflammatory wound dressings. The fibers are first subjected to aminolysis in order to obtain amino moieties on the surface, able to react with the molecules of FA. Next, the FA was attached to the aminolyzed fibers surface with use of 1-ethyl-3–(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide. The anti-inflammatory properties of the modified fibers were assessed using 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay. Presence of FA on the fibers’ surface was investigated through X-ray photoelectron spectroscopy analysis and Folin–Ciocalteu (total phenolic content) test.
- ItemStrontium substitution of gelatin modified calcium hydrogen phosphates as porous hard tissue substitutes(New York, NY [u.a.] : Wiley, 2020) Kruppke, Benjamin; Heinemann, Christiane; Gebert, Annett; Rohnke, Marcus; Weiß, Manuel; Henß, Anja; Wiesmann, Hans-Peter; Hanke, ThomasAiming at the generation of a high strontium-containing degradable bone substitute, the exchange of calcium with strontium in gelatin-modified brushite was investigated. The ion substitution showed two mineral groups, the high-calcium containing minerals with a maximum measured molar Ca/Sr ratio of 80%/20% (mass ratio 63%/37%) and the high-strontium containing ones with a maximum measured molar Ca/Sr ratio of 21%/79% (mass ratio 10%/90%). In contrast to the high-strontium mineral phases, a high mass loss was observed for the calcium-based minerals during incubation in cell culture medium (alpha-MEM), but also an increase in strength owing to dissolution and re-precipitation. This resulted for the former in a decrease of cation concentration (Ca + Sr) in the medium, while the pH value decreased and the phosphate ion concentration rose significantly. The latter group of materials, the high-strontium containing ones, showed only a moderate change in mass and a decrease in strength, but the Ca + Sr concentration remained permanently above the initial calcium concentration in the medium. This might be advantageous for a future planned application by supporting bone regeneration on the cellular level. © 2020 The Authors. Journal of Biomedical Materials Research Part A published by Wiley Periodicals LLC.
- ItemHelium transmission rate as a rapid and reliable method for assessing the water vapour transmission rate of transparent PET-SiOx barrier foils(New York, NY [u.a.] : Wiley, 2021) Herbst, Florian; Großer, Stephan; With, Patrick C.; Prager, Lutz; Pander, MatthiasA single quadrupole mass spectrometer coupled measuring setup was developed for the investigation of the helium transmission rate (HeTR) of SiOx-coated polyethylene terephthalate (PET) barrier films. The setup allows the pressure-less and time-resolved measurements of the helium permeation at transient and steady-state conditions. Whereas standard water vapour transmission rate (WVTR) experiments took extended test times (in the range of several days), HeTR measurements were finished after 1 h. For the material system investigated here, an excellent linear correlation of WVTR and HeTR was proven over two orders of magnitude (regarding WVTR). Experiments with application of different strain loads on the coated films revealed a significant increase of both, HeTR and WVTR. Scanning electron microscope (SEM) measurements evidenced multiple ruptures of the SiOx coating depending on the applied strain and initial thickness of the SiOx layer. Considering virgin barrier films and strain-ruptured barrier films, a good correlation of WVTR and HeTR was shown.
- ItemAbsence of percolation in graphs based on stationary point processes with degrees bounded by two(New York, NY [u.a.] : Wiley, 2022) Jahnel, Benedikt; Tóbiás, AndrásWe consider undirected graphs that arise as deterministic functions of stationary point processes such that each point has degree bounded by two. For a large class of point processes and edge-drawing rules, we show that the arising graph has no infinite connected component, almost surely. In particular, this extends our previous result for signal-to-interference ratio graphs based on stabilizing Cox point processes and verifies the conjecture of Balister and Bollobás that the bidirectional k-nearest neighbor graph of a two-dimensional homogeneous Poisson point process does not percolate for k=2.
- ItemA large-deviations principle for all the cluster sizes of a sparse Erdős-Rényi graph(New York, NY [u.a.] : Wiley, 2021) Andreis, Luisa; König, Wolfgang; Patterson, Robert I. A.[For Abstract, see PDF]
- ItemVariations in sustainable development goal interactions: Population, regional, and income disaggregation(New York, NY [u.a.] : Wiley, 2020) Warchold, Anne; Pradhan, Prajal; Kropp, Jürgen P.To fulfill the 2030 Agenda, the complexity of sustainable development goal (SDG) interactions needs to be disentangled. However, this understanding is currently limited. We conduct a cross-sectional correlational analysis for 2016 to understand SDG interactions under the entire development spectrum. We apply several correlation methods to classify the interaction as synergy or trade-off and characterize them according to their monotony and linearity. Simultaneously, we analyze SDG interactions considering population, location, income, and regional groups. Our findings highlight that synergies always outweigh trade-offs and linear outweigh non-linear interactions. SDG 1, 5, and 6 are associated with linear synergies, SDG 3, and 7 with non-linear synergies. SDG interactions vary according to a country's income and region along with the gender, age, and location of its population. In summary, to achieve the 2030 Agenda the detected interactions and inequalities across countries need be tracked and leveraged to “leave no one behind.”