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International Journal of Disaster Risk Science 2014年第3期5卷 227-241页

作者： Sina keller andreas Atzl Institute of Regional Science/Institute of Urban and Regional Planning Karlsruhe Institute of TechnologyKaiserstraße 1276131 KarlsruheGermany

Infrastructures in Europe have been affected by impacts of extreme natural events with increasing frequency over the past decades. One of the most recent examples is the flooding that affected parts of Germany in June 2013. Global warming is expected to change patterns of climate-related extreme events affecting *** article presents an explanatory approach. Based on an observational design, causal connections between the occurrence and patterns of extreme events and related road infrastructure impacts are analyzed. The hazard mapping case study in the state of Baden-Wrttemberg combines traffic information and data on the June 2013 extreme precipitation in Germany. It examines the precipitation occurrence and road infrastructure impact characteristics in Baden-Wu¨ rttemberg and identifies spatiotemporal hazard patterns. The article suggests further research needs and fields of application for risk mapping in climate change adaptation research in Germany.

关键词： Extreme precipitation Floods Germany Hazard patterns Landslides Road infrastructure

Note on:“Ballistic model for the prediction of penetration depth and residual velocity in adobe:A new interpretation of the ballistic resistance of earthen masonry”

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Defence Technology（防务技术） 2024年第1期31卷 607-609页

作者： andreas Heine Matthias Wickert Fraunhofer EMI Ernst-Zermelo-Str.479104FreiburgGermany

A recently published modeling approach for the penetration into adobe and previous approaches implicitly criticized are reviewed and *** article contains a note on the paper titled“Ballistic model for the prediction of penetration depth and residual velocity in adobe:A new interpretation of the ballistic resistance of earthen masonry”(DOI:https://***/10.1016/***.2018.07.017).Reply to the Note from Li Piani et al is linked to this article.

关键词： adobe prediction earth

Superior LSPR substrates based on electromagnetic decoupling for on-a-chip high-throughput label-free biosensing

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Light(Science & Applications) 2017年第1期6卷 585-592页

作者： Srdjan S Aćimović Hana Šípová Gustav Emilsson andreas B Dahlin Tomasz J Antosiewicz Mikael käll Department of Physics Chalmers University of Technology41296 GöteborgSweden Department of Chemistry and Chemical Engineering Chalmers University of Technology41296 GöteborgSweden Centre of New Technologies University of WarsawBanacha 2c02-097 WarsawPoland

Localized surface plasmon resonance(LSPR)biosensing based on supported metal nanoparticles offers unparalleled possibilities for high-end miniaturization,multiplexing and high-throughput label-free molecular interaction analysis in real time when integrated within an opto-fluidic ***,such LSPR-sensing devices typically contain extremely large regions of dielectric materials that are open to molecular adsorption,which must be carefully blocked to avoid compromising the device *** address this issue,we made the support essentially invisible to the LSPR by carefully removing the dielectric material overlapping with the localized plasmonic fields through optimized *** resulting LSPR substrate,which consists of gold nanodisks centered on narrow SiO2 pillars,exhibits markedly reduced vulnerability to nonspecific substrate adsorption,thus allowing,in an ideal case,the implementation of thicker and more efficient passivation *** demonstrate that this approach is effective and fully compatible with state-of-the-art multiplexed real-time biosensing technology and thus represents the ideal substrate design for high-throughput label-free biosensing systems with minimal sample consumption.

关键词： biosensing hyperspectral lab-on-a-chip LSPR nonspecific adsorption

Morphology and electric potential-induced mechanical behavior of metallic porous nanostructures

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Friction 2020年第3期8卷 604-612页

作者： Sunghan kIM andreas APOLYCARPOU Hong LIANG School of Mechanical Engineering Chung Ang UniversinSeoul 06974Republic of Korea Department of Mechanical Engineering Texas A&M UniversiyCollege Sation 77843-3123USA

Understanding mechanical behaviors influenced by electric potential and tribological contacts is important for verifying the robustness and reliability of applications based on metallic porous nanostructures in electrical *** this work,nickel-based metallic porous nanostructures were studied to characterize their mechanical properties and morphologically dependent contact areas during application of an electric potential using a nanoindenter.W e observed that the indentation moduli of nickel-based metallic porous nanostructures were altered by pore size and application of electric *** addition,the structural aspects of the surface morphology of nickel-based porous nanostructures had a critical effect on the determination of contact area.W e suggest that the relation between electric potential and the mechanical behaviors of metallic porous nanostructures can be crucial for building mechanically robust functional devices,which are influenced by electric *** morphological shape characteristics of metallic porous nanostructures can be alternative decisive factors for manipulation of tribological performance through regulation of contact area.

关键词： mechanical properties nanoindentation metallic porous nanostructures contact area electric potentia

Quasi-optimal control of a solar thermal system via neural networks✩

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Energy and AI 2023年第2期12卷 128-144页

作者： Jana Friese Niklas Brandt andreas Schulte Christian kirches Wilhelm Tegethoff Jürgen köhler Technische Universität Braunschweig Institut für ThermodynamikHans–Sommer–Straße 538106 BraunschweigGermany Technische Universität Braunschweig Institut für Mathematische OptimierungUniversitätsplatz 238106 BraunschweigGermany

The optimal control of complex thermal energy systems is a challenge due to their dynamic behavior andconstantly changing boundary conditions. To maximize the energy efficiency of such a dynamic system, optimaltrajectories for the controlled variables are needed. Extensive system knowledge is required to model the systemaccurately enough to be able to compute optimal trajectories. The high computational cost of computingoptimal control solutions with traditional approaches, especially with changing boundary conditions, oftenmakes this approach unusable for applications with limited computational power, such as real-time applicationson electronic control units (ECUs). This study investigates a possible solution to this challenge using a simplifiedexample system. Optimal control solutions for different boundary and initial conditions are generated forthe selected solar thermal system using a direct multiple shooting algorithm. Based on Bellman’s optimalityprinciple, the generated solutions are transformed into a data set of optimal state–action pairs. On this basis,different types of neural networks are trained, specifically a feed-forward, a recurrent, and a radial basisfunction network. Thus, data generation and training can be performed offline, and the required online computations are significantly reduced since the evaluation of a trained neural network requires comparatively lowcentral processing unit (CPU) power. The trained neural network controllers are tested for their ability to outputnear-optimal control actions based on the current system state. The feed-forward and recurrent neural networksshow promising initial results in this regard. Open questions and the need for improvements are discussed.

关键词： Optimal control Neural networks Bellmann equation Thermal systems Optimization

Structural and microstructural description of relaxor-ferroelectric transition in quenched Na_(1/2)Bi_(1/2)TiO_(3)-BaTiO_(3)

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Journal of Materiomics 2022年第4期8卷 823-832页

作者： andreas Wohninsland Ann-katrin Fetzer Rachel Broughton Jacob L.Jones k.V.Lalitha Department of Materials-and Geosciences Technical University of Darmstadt64287DarmstadtGermany Department of Materials Science and Engineering North Carolina State UniversityRaleighNC27695USA

Quenching lead-free Na_(1/2)Bi_(1/2)TiO_(3)-based ceramics from sintering temperature is established to increasethe depolarization temperature,Td and the lattice *** situ synchrotron X-ray diffractionmeasurements were carried out on furnace cooled and quenched Na_(1/2)Bi_(1/2)TiO_(3)-BaTiO_(3)(NBT-BT)with 6and 9 mol.%BT to discern the field-induced ferroelectric *** fractions were determined fromfull pattern Rietveld refinements and utilized together with the change in unit cell volume to calculatevolumetric strain resulting from phase ***-6BT demonstrates a cubic symmetry in thefurnace cooled state but quenching stabilizes the rhombohedral R3c phase and delays the formation of afield-induced,long range-ordered tetragonal phase,thereby shifting the onset of macroscopic strain tohigher fields.A field-induced phase transition from a weakly distorted rhombohedral to tetragonal phasecan be observed in furnace cooled ***,this phase transition cannot be detected inquenched NBT-9BT,since the ferroelectric tetragonal P4mm phase is stabilized in the initial *** to the furnace cooled materials,both the quenched compositions exhibit overall negligiblevolumetric strain as a function of electric ***,scanning electron micrographs of chemi-cally etched,poled and unpoled samples reveal an increased lamellar domain contrast in the *** these findings strengthen the hypothesis of a stabilized ferroelectric order resulting in theabsence of a field-induced phase transformation in quenched NBT-BT.

关键词： Lead-free Quenching Na_(1/2)Bi_(1/2)TiO_(3)-BaTiO_(3) Synchrotron diffraction Ferroelectric

Roughness Measurements with Polychromatic Speckles on Tilted Surfaces

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Nanomanufacturing and Metrology 2021年第4期4卷 237-246页

作者： Johannes Stempin andreas Tausendfreund Dirk Stobener andreas Fischer Bremen Institute for Metrology Automation and Quality ScienceUniversity of BremenLinzer Str.1328359 BremenGermany

Surface light scattering enables contactless and fast measurements of surface roughness.A surface inclination alters the direction of the scattering beam and thus the measured surface roughness is calculated from the detected intensity ***,an accurate sensor-surface alignment is *** order to achieve tilt-independent roughness measurements,a model-based evaluation approach for polychromatic speckle patterns is *** evaluating the shape of the superposed speckles,which occur for polychromatic illumination,with regard to the distance to the scattering centre,surfaces with an Sa roughness value in the range of 0.8-3.2μm are *** investigations demonstrate that the influence of a surface tilt up to±1.25°on the roughness measurement is reduced by 90%.As a result,the robustness of the polychromatic speckle roughness measurement is improved,which allows to speed up the adjustment of the measurement system or the surface sample,respectively.

关键词： Surface roughness Polychromatic light scattering Surface tilting In-process measurement

Odd-even effects in the structure and properties of aryl-substituted aliphatic self-assembled monolayers

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Nano Research 2024年第5期17卷 4231-4243页

作者： Piotr Cyganik andreas Terfort Michael Zharnikov Jagiellonian University Faculty of PhysicsAstronomy and Applied Computer ScienceSmoluchowski Institute of PhysicsŁojasiewicza 1130-348 KrakówPoland Institut für Anorganische und Analytische Chemie Universität FrankfurtMax-von-Laue-Straße 760438 FrankfurtGermany Applied Physical Chemistry Heidelberg UniversityIm Neuenheimer Feld 25369120 HeidelbergGermany

Self-assembled monolayers(SAMs)represent an important tool in context of nanofabrication and molecular engineering of surfaces and *** properties of functional SAMs depend not only on the character of the tail groups at the SAM-ambient interface,but are also largely defined by their *** its turn,the latter parameter results from a complex interplay of the structural forces and a variety of other factors,including so called odd-even effects,*** of the SAM structure and properties on the parity of the number(odd or even)of individual building blocks in the backbone of the SAM *** most impressive manifestation of the odd-even effects is the structure of aryl-substituted alkanethiolate SAMs on Au(111)and Ag(111),in which,in spite of the fact that the intermolecular interaction is mostly determined by the aryl part of the monolayers,one observes a pronounced dependence of molecular inclination and,consequently,the packing density of the SAM-forming molecules on the parity of number of methylene units in the alkyl *** we review the properties of the above systems as well as address fundamental reasons behind the odd-even effects,including the existence of a so-called bending potential,which is frequently disregarded in analysis of the structure-building *** generality of the odd-even effects in SAMs is additionally supported by the recent data for SAMs on GaAs,scanning tunneling microscopy data for SAMs on Ag(111),and the data for the monolayers with selenolate and carboxyl anchoring groups on Au(111)and Ag(111).The implications of these effects in terms of the control over the packing density and orientation of the tail groups at the SAM-ambient interface,structural perfection,polymorphism,temperature-driven phase transitions,and SAM stability toward such factors as ionizing radiation,exchange reaction,and electrochemical desorption are *** implications place the odd-even effects as an important tool

关键词： self-assembled monolayers molecular films surface and interface engineering odd-even-effects

Evaluating performance of lignite pillars with 2D approximation techniques and 3D numerical analyses

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International Journal of Mining Science and Technology 2017年第6期27卷 929-936页

作者： Deliveris Alexandros V. Benardos andreas Centre for Research and Technology Hellas (CERTH) Chemical Process & Energy Resources Institute (CPERI) Athens GR15 125 Greece National Technical University of Athens (NTUA) School of Mining and Metallurgical Engineering (SMME) Athens GR15 780 Greece

This paper attempts to investigate the use of approximate 2D numerical simulation techniques for the evaluation of lignite pillar geomechanical response, formed via the room and pillar mining *** and applicability of the developing methodology are assessed through benchmarking with a more direct and accurate 3D numerical model. This analysis utilizes an underground lignite mine which is being developed in soft rock environment. Through the decisions made for the optimum room and pillar layout, the design process highlights the strong points and the weaknesses of 2D finite element analysis, and provides useful recommendations for future reference. The interpretations of results demonstrate that 2D approximation techniques come near quite well to the actual 3D ***, external load approximation technique seems to fit even better with the respective outcomes from the 3D analyses.

关键词： Geomechanics Room and pillar Underground lignite mine Finite element method 3D numerical analysis Average pillar stress

A Method for the Determination of Turbulence Intensity by Means of a Fast Response Pressure Probe and its Application in a LP Turbine

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Journal of Thermal Science 2012年第1期21卷 21-31页

作者： Davide Lengani Berardo Paradiso andreas Marn Inst. f. Thermal Turbomachinery and Machine Dynamics Graz University of Technology

This paper describes the measurements and the post-processing procedure adopted for the determination of the turbulence intensity in a low pressure turbine (LPT) by means of a single sensor fast response aerodynamic pressure probe. The rig was designed in cooperation with MTU Aero Engines and considerable efforts were put into the adjustment of all relevant model parameters. Blade count ratio, airfoil aspect ratio, reduced massflow, reduced speed, inlet turbulence intensity and Reynolds numbers were chosen to reproduce the full scale LP turbine. Measurements were performed adopting a phase-locked acquisition technique in order to provide the time resolved flow field downstream of the turbine rotor. The total pressure random fluctuations are obtained by selectively filtering, in the frequency domain, the deterministic unsteadiness due to the rotor blades and coherent structures. The turbulence intensity is derived from the inverse Fourier transform and the correlations between total pressure and velocity fluctuations. The determination of the turbulence intensity allows the discussion of the interaction processes between the stator and rotor for engine-representative operating conditions of the turbine.

关键词： Turbulence fast response aerodynamic pressure probe low pressure turbine.