TY - JOUR A1 - Grassl, Sandra A1 - Ritter, Christoph A1 - Schulz, Alexander T1 - The nature of the Ny-Alesund wind field analysed by high-resolution windlidar data JF - Remote sensing N2 - In this work we present windlidar data for the research village Ny-Alesund located on Svalbard in the European Arctic (78.923 degrees N, 11.928 degrees F) from 2013 to 2021. The data have a resolution of 50 m and 10 min with an overlapping height of about 150 m. The maximum range depends on the meteorologic situation. Up to 1000 m altitude the data availability is better than 71%. We found that the highest wind speeds occur in November and December, the lowest ones in June and July, up to 500 m altitude the wind is channelled strongly in ESE to NW direction parallel to the fjord axis and the synoptic conditions above 1000 m altitude already dominate. While the fraction of windy days (v > 10 m/s) varies significantly from month to month, there is no overall trend of the wind visible in our data set. We define gusts and jets by the requirement of wind maxima v > 2 m/s above and below a wind maximum. In total, more than 24,000 of these events were identified (corresponding to 6% of the time), of which 223 lasted for at least 100 min ("Long Jets"). All of these events are fairly equally distributed over the months relatively to the available data. Further, gusts and jets follow different distributions (in terms of altitude or depths) and occur more frequently for synoptic flow from roughly a southerly direction. Jets do not show a clear correlation between occurrence and synoptic flow. Gusts and jets are not related to cloud cover. We conclude that the atmosphere from 400 m to 1000 m above Ny-Alesund is dominated by a turbulent wind shear zone, which connects the micrometeorology in the atmospheric boundary layer (ABL) with the synoptic flow. KW - windlidar KW - wind field KW - wind channelling KW - jets KW - Ny-Alesund KW - Svalbard KW - Kongsfjord KW - wind speed KW - wind direction KW - turbulent wind shear zone Y1 - 2022 U6 - https://doi.org/10.3390/rs14153771 SN - 2072-4292 VL - 14 IS - 15 PB - MDPI CY - Basel ER - TY - JOUR A1 - Karwinkel, Thiemo A1 - Winklhofer, Michael A1 - Janner, Lars Erik A1 - Brust, Vera A1 - Hüppop, Ommo A1 - Bairlein, Franz A1 - Schmaljohann, Heiko T1 - A magnetic pulse does not affect free-flight navigation behaviour of a medium-distance songbird migrant in spring JF - The journal of experimental biology N2 - Current evidence suggests that migratory animals extract map information from the geomagnetic field for true navigation. The sensory basis underlying this feat is elusive, but presumably involves magnetic particles. A common experimental manipulation procedure consists of pre-treating animals with a magnetic pulse, with the aim of re-magnetising particles to alter the internal representation of the external field prior to a navigation task. Although pulsing provoked deflected bearings in caged songbirds, analogous studies with free-flying songbirds yielded inconsistent results. Here, we pulsed European robins (Erithacus rubecula) at an offshore stopover site during spring migration and monitored their free-flight behaviour with a regional-scale network of radio-receiving stations. We found no pulse effect on departure probability, nocturnal departure timing departure direction or consistency of flight direction. This suggests either no use of the geomagnetic map by our birds, or that magnetic pulses do not affect the sensory system underlying geomagnetic map detection. KW - bird migration KW - magnetic map KW - magnetic-particlebased sensor KW - magnetic pulse KW - magnetoreception KW - navigation Y1 - 2022 U6 - https://doi.org/10.1242/jeb.244473 SN - 0022-0949 SN - 1477-9145 VL - 225 IS - 19 PB - Company of Biologists CY - Cambridge ER - TY - JOUR A1 - Sorgenfrei, Nomi A1 - Giangrisostomi, Erika A1 - Kühn, Danilo A1 - Ovsyannikov, Ruslan A1 - Föhlisch, Alexander T1 - Time and angle-resolved time-of-flight electron spectroscopy for functional materials science JF - Molecules : a journal of synthetic chemistry and natural product chemistry N2 - Electron spectroscopy with the unprecedented transmission of angle-resolved time-of-flight detection, in combination with pulsed X-ray sources, brings new impetus to functional materials science. We showcase recent developments towards chemical sensitivity from electron spectroscopy for chemical analysis and structural information from photoelectron diffraction using the phase transition properties of 1T-TaS2. Our development platform is the SurfaceDynamics instrument located at the Femtoslicing facility at BESSY II, where femtosecond and picosecond X-ray pulses can be generated and extracted. The scientific potential is put into perspective to the current rapidly developing pulsed X-ray source capabilities from Lasers and Free-Electron Lasers. KW - photoelectron spectroscopy KW - surface science KW - time-resolved KW - ultrafast KW - instrumentation KW - dichalcogenides KW - phase transition Y1 - 2022 U6 - https://doi.org/10.3390/molecules27248833 SN - 1420-3049 VL - 27 IS - 24 PB - MDPI CY - Basel ER - TY - JOUR A1 - Lever, Fabiano A1 - Mayer, Dennis A1 - Metje, Jan A1 - Alisauskas, Skirmantas A1 - Calegari, Francesca A1 - Düsterer, Stefan A1 - Feifel, Raimund A1 - Niebuhr, Mario A1 - Manschwetus, Bastian A1 - Kuhlmann, Marion A1 - Mazza, Tommaso A1 - Robinson, Matthew Scott A1 - Squibb, Richard J. A1 - Trabattoni, Andrea A1 - Wallner, Måns A1 - Wolf, Thomas J. A. A1 - Gühr, Markus T1 - Core-level spectroscopy of 2-thiouracil at the sulfur L1 and L2,3 edges utilizing a SASE free-electron-laser JF - Molecules N2 - In this paper, we report X-ray absorption and core-level electron spectra of the nucleobase derivative 2-thiouracil at the sulfur L1- and L2,3-edges. We used soft X-rays from the free-electron laser FLASH2 for the excitation of isolated molecules and dispersed the outgoing electrons with a magnetic bottle spectrometer. We identified photoelectrons from the 2p core orbital, accompanied by an electron correlation satellite, as well as resonant and non-resonant Coster–Kronig and Auger–Meitner emission at the L1- and L2,3-edges, respectively. We used the electron yield to construct X-ray absorption spectra at the two edges. The experimental data obtained are put in the context of the literature currently available on sulfur core-level and 2-thiouracil spectroscopy. KW - X-ray KW - photoelectron KW - sulfur KW - thiouracil KW - nucleobases KW - Coster–Kronig KW - Auger–Meitner KW - NEXAFS KW - FLASH Y1 - 2021 U6 - https://doi.org/10.3390/molecules26216469 SN - 1420-3049 VL - 26 IS - 21 PB - MDPI CY - Basel ER - TY - JOUR A1 - Tian, Peibo A1 - Liang, Yingjie T1 - Material coordinate driven variable-order fractal derivative model of water anomalous adsorption in swelling soil JF - Chaos, solitons & fractals N2 - The diffusion process of water in swelling (expansive) soil often deviates from normal Fick diffusion and belongs to anomalous diffusion. The process of water adsorption by swelling soil often changes with time, in which the microstructure evolves with time and the absorption rate changes along a fractal dimension gradient function. Thus, based on the material coordinate theory, this paper proposes a variable order derivative fractal model to describe the cumulative adsorption of water in the expansive soil, and the variable order is time dependent linearly. The cumulative adsorption is a power law function of the anomalous sorptivity, and patterns of the variable order. The variable-order fractal derivative model is tested to describe the cumulative adsorption in chernozemic surface soil, Wunnamurra clay and sandy loam. The results show that the fractal derivative model with linearly time dependent variable-order has much better accuracy than the fractal derivative model with a constant derivative order and the integer order model in the application cases. The derivative order can be used to distinguish the evolution of the anomalous adsorption process. The variable-order fractal derivative model can serve as an alternative approach to describe water anomalous adsorption in swelling soil. KW - water adsorption KW - variable order KW - fractal derivative KW - swelling soil KW - material coordinate Y1 - 2022 U6 - https://doi.org/10.1016/j.chaos.2022.112754 SN - 0960-0779 SN - 1873-2887 VL - 164 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Schneider, Sebastian A1 - Bytyqi, Kushtrim A1 - Kohaut, Stephan A1 - Bügel, Patrick A1 - Weinschenk, Benjamin A1 - Marz, Michael A1 - Kimouche, Amina A1 - Fink, Karin A1 - Hoffmann-Vogel, Regina T1 - Molecular self-assembly of DBBA on Au(111) at room temperature JF - Physical chemistry, chemical physics : a journal of European Chemical Societies N2 - We have investigated the self-assembly of the graphene nanoribbon molecular precursor 10,10'-dibromo-9,9'-bianthryl (DBBA) on Au(111) with frequency modulation scanning force microscopy (FM-SFM) at room temperature combined with ab initio calculations. For low molecular coverages, the molecules aggregate along the substrate herringbone reconstruction main directions while remaining mobile. At intermediate coverage, two phases coexist, zigzag stripes of monomer chains and decorated herringbones. For high coverage, the molecules assemble in a dimer-striped phase. The adsorption behaviour of DBBA molecules and their interactions are discussed and compared with the results from ab initio calculations. Y1 - 2022 U6 - https://doi.org/10.1039/d2cp02268k SN - 1463-9076 SN - 1463-9084 VL - 24 IS - 46 SP - 28371 EP - 28380 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Rothe, Martin A1 - Zhao, Yuhang A1 - Halim, Henry A1 - Lu, Yan A1 - Benson, Oliver T1 - Spatial mapping of bleaching in a metal-organic plasmon converter JF - Optics continuum N2 - Hybrid nanophotonic elements, fabricated by organic and inorganic materials, are going to be key components of modern devices. Coupled systems of photoemitters with a plasmonic waveguide serve the demand for nanoscopic frequency converters. However, processes like the degradation of the photoemitters via photobleaching occur and need to be monitored and controlled, to realize future successful devices. We introduce a hybrid perylene-diimide / silver nanowire as plasmon frequency converter. A versatile method is presented to monitor and analyze the bleaching process. It is based on a time series of photoluminescence images, during the operation of a single converter. An analytical model is applied on the data and unveils that the photobleaching rate is constant and independent of the operation of the plasmon converter. Y1 - 2022 U6 - https://doi.org/10.1364/OPTCON.454911 SN - 2770-0208 VL - 1 IS - 8 SP - 1730 EP - 1740 PB - Optica Publishing Group CY - Washington ER - TY - JOUR A1 - Voloskov, Boris A1 - Mishurova, Tatiana A1 - Evlashin, Stanislav A1 - Akhatov, Iskander A1 - Bruno, Giovanni A1 - Sergeichev, Ivan T1 - Artificial defects in 316L stainless steel produced by laser powder bed fusion: printability, microstructure, and effects on the very-high-cycle fatigue behavior JF - Advanced engineering materials N2 - The printability of artificial defects inside the additively manufactured laser powder bed fusion (LPBF) 316L stainless steel is investigated. The printing parameters of the LPBF process are optimized to produce artificial defects with reproducible sizes at desired positions while minimizing redundant porosity. The smallest obtained artificial defect is 90 mu m in diameter. The accuracy of the geometry of the printed defect depends on both the height and the diameter in the input model. The effect of artificial defects on the very-high-cycle fatigue (VHCF) behavior of LPBF 316L stainless steel is also studied. The specimens printed with artificial defects in the center are tested under VHCF using an ultrasonic machine. Crack initiation is accompanied by the formation of a fine granular area (FGA), typical of VHCF. Despite the presence of relatively large artificial defects, FGA formation is observed around accidental natural printing defects closer to the surface, which can still be considered as internal. The causes for this occurrence are discussed. KW - artificial defects KW - fine granular areas KW - fracture surfaces KW - laser powder bed fusion KW - very-high-cycle fatigue Y1 - 2022 U6 - https://doi.org/10.1002/adem.202200831 SN - 1438-1656 SN - 1527-2648 VL - 25 IS - 1 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Lepro, Valentino A1 - Großmann, Robert A1 - Panah, Setareh Sharifi A1 - Nagel, Oliver A1 - Klumpp, Stefan A1 - Lipowsky, Reinhard A1 - Beta, Carsten T1 - Optimal cargo size for active diffusion of biohybrid microcarriers JF - Physical Review Applied N2 - As society paves its way towards device miniaturization and precision medicine, microscale actuation and transport become increasingly prominent research fields with high impact in both technological and clinical contexts. In order to accomplish movement of micron-sized objects towards specific target sites, active biohybrid transport systems, such as motile living cells that act as smart biochemically powered microcarriers, have been suggested as an alternative to synthetic microrobots. Inspired by the motility of leukocytes, we propose the amoeboid crawling of eukaryotic cells as a promising mechanism for transport of micron-sized cargoes and present an in-depth study of this type of composite active matter. Its transport properties result from the interactions of an active element (cell) and a passive one (cargo) and reveal an optimal cargo size that enhances the locomotion of the load-carrying cells, even exceeding their motility in the absence of cargo. The experimental findings are rationalized in terms of a biohybrid active particle model that describes the emergent cell-cargo dynamics and enables us to derive the long-time diffusive transport of amoeboid microcarriers. As amoeboid locomotion is commonly observed for mammalian cells such as leukocytes, our results lay the foundations for the study of transport performance of other medically relevant cell types and for extending our findings to more advanced transport tasks in complex environments, such as tissues. Y1 - 2022 U6 - https://doi.org/10.1103/PhysRevApplied.18.034014 SN - 2331-7019 VL - 18 IS - 3 PB - American Physical Society CY - College Park ER - TY - JOUR A1 - Yan, Shengjie A1 - Liang, Yingjie A1 - Xu, Wei T1 - Characterization of chloride ions diffusion in concrete using fractional Brownian motion run with power law clock JF - Fractals : complex geometry, patterns, and scaling in nature and society N2 - In this paper, we propose a revised fractional Brownian motion run with a nonlinear clock (fBm-nlc) model and utilize it to illustrate the microscopic mechanism analysis of the fractal derivative diffusion model with variable coefficient (VC-FDM). The power-law mean squared displacement (MSD) links the fBm-nlc model and the VC-FDM via the two-parameter power law clock and the Hurst exponent is 0.5. The MSD is verified by using the experimental points of the chloride ions diffusion in concrete. When compared to the linear Brownian motion, the results show that the power law MSD of the fBm-nlc is much better in fitting the experimental points of chloride ions in concrete. The fBm-nlc clearly interprets the VC-FDM and provides a microscopic strategy in characterizing different types of non-Fickian diffusion processes with more different nonlinear functions. KW - mean squared displacement KW - anomalous diffusion KW - fractal derivative KW - fractional brownian motion KW - nonlinear clock Y1 - 2022 U6 - https://doi.org/10.1142/S0218348X22501778 SN - 0218-348X SN - 1793-6543 VL - 30 IS - 9 PB - World Scient. Publ. CY - Singapore [u.a.] ER -