bluuebunny/crossref_metadata_2025_split huggingface dataset:
Single‐Particle Tracking and Trajectory Analysis of Fluorescent Nanodiamonds in Cell‐Free Environment and Live Cells
Authors: Sigaeva Alina , Hochstetter Axel , Bouyim Sighom , Chipaux Mayeul , Stejfova Miroslava , Cigler Petr , Schirhagl Romana 
Published: August 2022

AbstractDiamond magnetometry can provide new insights on the production of free radicals inside live cells due to its high sensitivity and spatial resolution. However, the measurements often lack intracellular context for the recorded signal. In this paper, the possible use of single‐particle tracking and trajectory analysis of fluorescent nanodiamonds (FNDs) to bridge that gap is explored. It starts with simulating a set of different possible scenarios of a particle's movement, reflecting different modes of motion, degrees of confinement, as well as shapes and sizes of that confinement. Then, the insights from the analysis of the simulated trajectories are applied to describe the movement of FNDs in glycerol solutions. It is shown that the measurements are in good agreement with the previously reported findings and that trajectory analysis yields meaningful results, when FNDs are tracked in a simple environment. Then the much more complex situation of FNDs moving inside a live cell is focused. The behavior of the particles after different incubation times is analyzed, and the possible intracellular localization of FNDs is deducted from their trajectories. Finally, this approach is combined with long‐term magnetometry methods to obtain maps of the spin relaxation dynamics (or T1) in live cells, as FNDs move through the cytosol.
Effect of Catechin on the Retrogradation and Structural Properties of Chestnut Starch
Authors: Xie Yamin , Chen Jie , Xu Fei , Chen Ling , Cao Fei , Cui Chaoyue 
Published: August 2022

AbstractCatechin (EC) is a natural plant extract and has great health benefits. EC interacts with the starch isolated from Chinese chestnut to form complexes. The effect of EC addition on the structure and retrogradation properties of chestnut starch (CS) is investigated in this study. Compared with CS, when the addition of EC is 10%, the peak viscosity (PV), trough viscosity(TV), and setback (SB) of CS decreased by 45.65%, 39.95%, and 47.38% (2185.62, 922.35, and 445.42 cp), respectively. Thermogravimetric shows that the EC addition can decrease the degradation temperature of starch. Scanning electron microscope shows that EC can cause a looser gel structure of CS. The results of Fourier transform infrared show that the absorption peak of the complex at 3000–3600 cm−1 is enhanced to a high wavenumber. X‐ray diffraction results in a reduction in the relative crystallinity with the increase of EC addition. In summary, the overall results suggest CS interacted with EC to form the non‐inclusive complex, resulting in changes in starch structure. These results indicate that EC is a promising ingredient to restrain the retrogradation of starchy food and provides new insights for the application of other starch and polyphenols.
Density functionals based on the mathematical structure of the strong‐interaction limit of DFT
Authors: Vuckovic Stefan , Gerolin Augusto , Daas Kimberly J. , Bahmann Hilke , Friesecke Gero , Gori‐Giorgi Paola 
Published: August 2022

AbstractWhile in principle exact, Kohn–Sham density functional theory—the workhorse of computational chemistry—must rely on approximations for the exchange–correlation functional. Despite staggering successes, present‐day approximations still struggle when the effects of electron–electron correlation play a prominent role. The limit in which the electronic Coulomb repulsion completely dominates the exchange–correlation functional offers a well‐defined mathematical framework that provides insight for new approximations able to deal with strong correlation. In particular, the mathematical structure of this limit, which is now well‐established thanks to its reformulation as an optimal transport problem, points to the use of very different ingredients (or features) with respect to the traditional ones used in present approximations. We focus on strategies to use these new ingredients to build approximations for computational chemistry and highlight future promising directions.This article is categorized under:
Electronic Structure Theory > Density Functional Theory
Efficacy of ground‐based trapping of coastal American black bears in Prince William Sound, Alaska
Authors: Westing Charlotte L. , Skinner John P. , Burcham Milo G. 
Published: August 2022

AbstractGround‐based trapping can be the most practical approach for capturing American black bears (Ursus americanus) in remote portions of Alaska. During the summers of 2016–2018 we captured 106 black bears in a coastal portion of southcentral Alaska, USA, using bucket cable traps and Aldrich snare sets, 2 common foot snaring techniques. Despite widespread use, little research has focused on factors contributing to success and differences in safety for both foot snaring techniques. We compared trap engagement and success and found that bears engaged with bucket cable traps at a 31% (CL = 3–50%) lower rate than with Aldrich snare sets but once engaged were equally likely to be successfully snared. Prebaiting sites increased capture success 362% (CL = 21–1663%) but it was unclear if success improved when sites were prebaited multiple times. Regardless of trap type, bear engagement with sets were 194% higher (CL = 94–345%) during mid‐day hours (0800–1559) compared to crepuscular or nocturnal hours. We observed average injury scores of less than 11 points (out of 400 possible points) for both set types, consistent with the score given for minor lacerations. Both methods performed well within the recommended safety standards of the American Society of Mammalogists.
Europe in the U.S.-Russian Security Dilemma: Is There a Way Out?
Authors: Kunz Barbara 
Published: August 2022

AbstractOne implication of Europe’s security being coupled to that of the United States is Europe’s being part of the U.S.-Russian security dilemma, a notion at the heart of defensive realism. This has considerable implications for European security. Against the backdrop of current policy debates, this explorative essay seeks to analyze Europe’s policy options in this context. It concludes that Europe has no way to escape the U.S.-Russian security dilemma. This, however, does not leave Europeans without avenues for action in order to contribute to better management of that security dilemma. The chapter intends to bridge a gap between empirical debates on the future of the European security order and more theoretical takes on the emergence of a multipolar world and Europe’s role in it.
Modeling and Simulation of a Turbulent Multi-component Two-phase Flow Involving Phase Change Processes Under Supercritical Conditions
Authors: Kuetemeier Dennis , Sadiki Amsini 
Published: August 2022

AbstractThe present paper aims at developing a generally valid, consistent numerical description of a turbulent multi-component two-phase flow that experiences processes that may occur under both subcritical and trans-critical or supercritical operating conditions. Within an appropriate LES methodology, focus is put on an Euler-Eulerian method that includes multi-component mixture properties along with phase change process. Thereby, the two-phase flow fluid is considered as multi-component mixtures in which the real fluid properties are accounted for by a composite Peng-Robinson (PR) equation of state (EoS), so that each phase is governed by its own PR EoS. The suggested numerical modelling approach is validated while simulating the disintegration of an elliptic jet of supercritical fluoroketone injected into a helium environment. Qualitative and quantitative analyses are carried out. The results show significant coupled effect of the turbulence and the thermodynamic on the jet disintegration along with the mixing processes. Especially, comparisons between the numerical predictions and available experimental data provided in terms of penetration length, fluoroketone density, and jet spreading angle outline good agreements that attest the performance of the proposed model at elevated pressures and temperatures. Further aspects of transcritical jet flow case as well as comparison with an Eulerian-Lagrangian approach which is extended to integrate the arising effects of vanishing surface tension in evolving sprays are left for future work.
Experimental Investigation of Transient Injection Phenomena in Rocket Combusters at Vacuum with Cryogenic Flash Boiling
Authors: Rees Andreas , Oschwald Michael 
Published: August 2022

AbstractThe substitution of the toxic hydrazine in current high-altitude rocket engines like upper stages or reaction control thrusters by green propellants is a major key driver in the current technology development of rocket propulsion systems. Operating these kind of rocket engines at high-altitude leads to a sudden pressure drop in the liquid propellants during their injection into the combustion chamber with a near-vacuum atmosphere prior to ignition. The resulting superheated thermodynamic state of the liquid causes a fast and eruptive evaporation which is called flash boiling. The degree of atomisation is important for a successful ignition and a secure operation of the rocket engine. The development and operation of a cryogenic high-altitude test bench at DLR Lampoldshausen enables the systematical experimental characterization of cryogenic flash boiling due to its ability to adjust and control the injection parameters like temperature, pressure or geometry. Several test campaigns with liquid nitrogen (LN2) were performed using two optical diagnostic methods: First, flash boiling LN2 spray patterns were visualised by means of high-speed shadowgraphy and, secondly, we determined the droplet size and velocity distributions in strongly superheated LN2 sprays with the help of a laser-based Phase Doppler system (PDA). The experimental data generated within these measurement campaigns provide defined boundary conditions as well as a broad data base for the numerical modelling of cryogenic flash boiling like e.g. the publications [8, 9].
Modelling and Simulation of Flash Evaporation of Cryogenic Liquids
Authors: Gärtner Jan Wilhelm , Loureiro Daniel D. , Kronenburg Andreas 
Published: August 2022

AbstractRocket engine manufacturers attempt to replace toxic, hypergolic fuels by less toxic substances such as cryogenic hydrogen and oxygen. Such components will be superheated when injected into the combustion chamber prior to ignition. The liquids will flash evaporate and subsequent mixing will be crucial for a successful ignition of the engine. We now conduct a series of DNS and RANS-type simulations to better understand this mixing process including microscopic processes such as bubble growth, bubble-bubble interactions, spray breakup dynamics and the resulting droplet size distribution. Full scale RANS simulations provide further insight into effects associated with flow dynamic such as shock formation behind the injector outlet. Capturing these gas dynamic effects is important, as they affect the spray morphology and droplet movements.
Mass Transport Across Droplet Interfaces by Atomistic Simulations
Authors: Heinen Matthias , Homes Simon , Guevara-Carrion Gabriela , Vrabec Jadran 
Published: August 2022

AbstractDue to availability of powerful computers and efficient algorithms, physical processes occurring at the micrometer scale can nowadays be studied with atomistic simulations. In the framework of the collaborative research center SFB-TRR75 “Droplet dynamics under extreme ambient conditions”, investigations of the mass transport across vapour-liquid interfaces are conducted. Non-equilibrium molecular dynamics simulation is employed to study single- and two-phase shock tube scenarios for a simple noble gas-like fluid. The generated data show an excellent agreement with computational fluid dynamics simulations. Further, particle and energy flux during evaporation are sampled and analysed with respect to their dependence on the interface temperature, employing a newly developed method which ensures a stationary process. In this context, the interface properties between liquid nitrogen and hydrogen under strong gradients of temperature and composition are investigated. Moreover, the Fick diffusion coefficient of strongly diluted species in supercritical CO$$_{2}$$

2

is predicted by equilibrium molecular dynamics simulation and the Green-Kubo formalism. These results are employed to assess the performance of several predictive equations from the literature.
Numerical Simulation of Heat Transfer and Evaporation During Impingement of Drops onto a Heated Wall
Authors: Sontheimer Henrik , Schlawitschek Christiane , Batzdorf Stefan , Stephan Peter , Gambaryan-Roisman Tatiana 
Published: August 2022

AbstractIn this study, hydrodynamics and heat transport during the impact of single and multiple drops onto a hot wall are studied numerically. The heat transfer in the vicinity of the three-phase contact line, where solid, liquid and vapour meet, contributes significantly to the global heat transfer. The microscale processes in the region of the three-phase contact line are analysed using a lubrication approximation. The results in the form of correlations are integrated into an overall model. The impingement of drops on a macro scale is simulated using a numerical model developed within the OpenFOAM library. The influence of dimensionless parameters, i.e., the Reynolds, Weber, Bond, Prandtl and Jakob numbers, as well as the influence of pressure, on the transport phenomena is discussed. The analysis of the influence of drop frequency and substrate thickness during the vertical coalescence and the influence of the drop spacing during the horizontal coalescence of drops on the hot surface complete the study. The results contribute to a better understanding of the complex mechanisms of spray cooling.
Impact of Supercooled Drops onto Cold Surfaces
Authors: Gloerfeld Mark , Schremb Markus , Criscione Antonio , Jakirlic Suad , Tropea Cameron 
Published: August 2022

AbstractIce accretion resulting from the impact of supercooled water drops is a hazard for structures exposed to low temperatures, for instance aircraft wings and wind turbine blades. Despite a multitude of studies devoted to the involved phenomena, the underlying physical processes are not yet entirely understood. Hence, modelling of the conditions for ice accretion and prediction of the ice accretion rate are presently not reliable. The research conducted in this study addresses these deficiencies in order to lend insight into the physical processes involved. While presenting an overview of results obtained during the first funding periods of this project, new results are also presented, relating to the impact of supercooled drops onto a cold surface in a cold air flow. The experiments are conducted in a dedicated icing wind tunnel and involve measuring the residual mass after impact of a liquid supercooled drop exhibiting corona splash as well as the impact of dendritic frozen drops onto a solid surface.
Interaction of Drops and Sprays with a Heated Wall
Authors: Schmidt Johannes Benedikt , Breitenbach Jan , Roisman Ilia V. , Tropea Cameron 
Published: August 2022

AbstractSpray-wall interactions take place in many technical applications such as spray cooling, combustion processes, cleaning, wetting of surfaces, coating and painting, etc. The outcome of drop impact onto hot surfaces depends on a variety of parameters like for example material and thermal properties of the liquid and wall, substrate wetting properties, surrounding conditions which determine the saturation temperature, spray impact parameters and surface temperature. The aim of the current project is to improve knowledge of the underlying physics of spray-wall interactions. As an important step towards spray impact modeling first a single drop impact onto hot substrates is considered in detail. Various regimes of single drop impact, such as thermal atomization, magic carpet breakup, nucleate boiling and thermosuperrepellency, observed at different wall temperatures, ambient pressures and impact velocities, have been investigated experimentally and modelled theoretically during the project period. The heat flux, an important parameter for spray cooling, has been modeled not only for single drop impacts but also for sprays within many regimes. The models show a good agreement with experimental data as well as data from literature.
Interactive Visualization of Droplet Dynamic Processes
Authors: Heinemann Moritz , Sadlo Filip , Ertl Thomas 
Published: August 2022

AbstractThis article presents an overview of visual analysis techniques specifically developed for high-resolution direct numerical multiphase simulations in the droplet dynamic context. Visual analysis of such data covers a large range of tasks, starting from observing physical phenomena such as energy transport or collisions for single droplets to the analysis of large-scale simulations such as sprays and jets. With an increasing number of features, coalescence and breakup events might happen, which need to be visually presented in an interactive explorable way to gain a deeper insight into physics. But also the task of finding relevant structures, features of interest, or a general dataset overview becomes non-trivial. We present an overview of new approaches developed in our SFB-TRR 75 project A1 covering work from the last decade to the current work-in-progress. They are the basis for relevant contributions to visualization research as well as useful tools for close collaborations within the SFB.
Development of Numerical Methods for the Simulation of Compressible Droplet Dynamics Under Extreme Ambient Conditions
Authors: Jöns Steven , Fechter Stefan , Hitz Timon , Munz Claus-Dieter 
Published: August 2022

AbstractThe computation of two-phase flow scenarios in a high pressure and temperature environment is a delicate task, for both the physical modeling and the numerical method. In this article, we present a sharp interface method based on a level-set ghost fluid approach. Phase transition effects are included by the solution of the two-phase Riemann problem at the interface, supplemented by a phase transition model based on classical irreversible thermodynamics. We construct an exact Riemann solver, as well as an approximate Riemann solver. We compare numerical results against molecular dynamics data for an evaporation shock tube and a stationary evaporation case. In both cases, our numerical method shows a good agreement with the reference data.
Stopping Droplet Rebound with Polymer Additives: A Molecular Viewpoint
Authors: Lee Eunsang , Krishna Chilukoti Hari , Müller-Plathe Florian 
Published: August 2022

AbstractThe origin of rebound suppression of an impacting droplet by a small amount of polymer additive has been tentatively explained by various physical concepts including the dynamic surface tension, the additional energy dissipation by non-Newtonian elongational viscosity, the elastic force of stretched polymer, and the additional friction on a receding contact line. To better understand the role of polymer on a molecular level, we performed multi-body dissipative particle dynamics simulations of droplets impacting on solvophobic surfaces. The rebound suppression is achieved by the elastic force of stretched polymer during the hopping stage, and the additional friction on the contact line during the retraction stage. Both slow-hopping and slow-retraction mechanisms coexist in a wide range of simulation parameters, but the latter is prevailing for large droplets, and for the strong attraction strength between polymer and surface. The increased polymer adsorption, which maybe achieved by a higher polymer concentration or a larger molecular weight, stimulates both mechanisms. Also, the molecular evidence of the additional friction on the receding contact line is shown from the relation between the contact angle and the contact line velocity where the slope of the fitted line is an indication of the additional friction.
Modelling of Droplet Dynamics in Strong Electric Fields
Authors: Gjonaj Erion , Ouedraogo Yun , Schöps Sebastian 
Published: August 2022

AbstractWe describe a modelling approach for the simulation of droplet dynamics in strong electric fields. The model accounts for electroquasistatic fields, convective and conductive currents, contact angle dynamics and charging effects associated with droplet breakup processes. Two classes of applications are considered. The first refers to the problem of water droplet oscillations on the surface of outdoor high-voltage insulators. The contact angle characteristics resulting from this analysis provides a measure for the estimation of the electric field inception thresholds for electrical discharges on the surface. The second class of applications consists in the numerical characterization of electrosprays. Detailed simulations confirm the scaling law for the first electrospray ejection and, furthermore, provide insight on the charge-radius characteristics for transient as well as steady state electrosprays.
Modelling and Numerical Simulation of Binary Droplet Collisions Under Extreme Conditions
Authors: Potyka Johanna , Kromer Johannes , Liu Muyuan , Schulte Kathrin , Bothe Dieter 
Published: August 2022

AbstractThe complexity of binary droplet collisions strongly increases in case of immiscible liquids with the occurrence of triple lines or for high energetic collisions, where strong rim instabilities lead to the spattering of satellite droplets. To cope with such cases, the Volume of Fluid method is extended by an efficient interface reconstruction, also applicable to multi-material cells of arbitrary configuration, as well as an enhanced continuous surface stress model for accurate surface force computations, also applicable to thin films. For collisions of fully wetting liquids, excellent agreement to experimental data is achieved in different collision regimes. High-resolution simulations predict droplet collisions in the spattering regime and provide detailed insights into the evolution of the rim instability. Another challenge is the numerical prediction of the collision outcome in the bouncing or coalescence region, where the rarefied gas dynamics in the thin gas film determines the collision result. To this end, an important step forward became possible by modelling the pressure in the gas film. With the introduction of an interior collision plane within the flow domain, it is now possible to simulate droplet collisions with gas film thickness reaching the physically relevant length scale.
Afterword: Man Up/Stand Up
Authors: Almassi Ben 
Published: August 2022

AbstractTo conclude, we contrast feminist allyship masculinity with a familiar expression of hegemonic masculinity: the exhortation to “man up!” Both have normative force; both capture and convey expectations (patriarchal, feminist, or otherwise) of how men should be. But what differentiates feminist allyship as nontoxic masculinity is the sort of normative direction it gives: not to man up, but to stand up for gender justice from our situated positions and distinctive capacities as men in patriarchal societies.