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See detailDisruption of Electrospinning due to Water Condensation into the Taylor Cone.
Reyes, C. G.; Lagerwall, Jan UL

in ACS Applied Materials and Interfaces (2020), 12(23), 26566--26576

The well-known problems of electrospinning hygroscopic polymer fibers in humid air are usually attributed to water condensing onto the jet mid-flight: water enters the jet as an additional solvent ... [more ▼]

The well-known problems of electrospinning hygroscopic polymer fibers in humid air are usually attributed to water condensing onto the jet mid-flight: water enters the jet as an additional solvent, hindering solidification into well-defined fibers. Here, we show that fiber fusion and shape loss seen at the end of the process may actually stem from water already condensing into the Taylor cone from where the jet ejects, if the solvent is volatile and miscible with water, for example, ethanol. The addition of water can radically change the solvent character from good to poor, even if water on its own is an acceptable solvent. Moreover, and counterintuitively, the water condensation promotes solvent evaporation because of the release of heat through the phase transition as well as from the exothermic mixing process. The overall result is that the polymer solution develops a gel-like skin around the Taylor cone. The situation is significantly aggravated in the case of coaxial electrospinning to make functional composite fibers if the injected core fluid forms a complex phase diagram with miscibility gaps together with the polymer sheath solvent and the water condensing from the air. The resulting phase separation coagulates the polymer throughout the Taylor cone, as liquid droplets with different compositions nucleate and spread, setting up strong internal flows and concentration gradients. We demonstrate that these cases of uncontrolled polymer coagulation cause rapid Taylor cone deformation, multiple jet ejection, and the inability to spin coaxial fiber mats, illustrated by the example of coaxial electrospinning of an ethanolic polyvinylpyrrolidone solution with a thermotropic liquid crystal core, at varying humidities. [less ▲]

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See detailFrom Equilibrium Liquid Crystal Formation and Kinetic Arrest to Photonic Bandgap Films Using Suspensions of Cellulose Nanocrystals
Schütz, Christina; Bruckner, Johanna R.; Honorato-Rios, Camila et al

in Crystals (2020), 10(3), 199

The lyotropic cholesteric liquid crystal phase developed by suspensions of cellulose nanocrystals (CNCs) has come increasingly into focus from numerous directions over the last few years. In part, this is ... [more ▼]

The lyotropic cholesteric liquid crystal phase developed by suspensions of cellulose nanocrystals (CNCs) has come increasingly into focus from numerous directions over the last few years. In part, this is because CNC suspensions are sustainably produced aqueous suspensions of a fully bio-derived nanomaterial with attractive properties. Equally important is the interesting and useful behavior exhibited by solid CNC films, created by drying a cholesteric-forming suspension. However, the pathway along which these films are realized, starting from a CNC suspension that may have low enough concentration to be fully isotropic, is more complex than often appreciated, leading to reproducibility problems and confusion. Addressing a broad audience of physicists, chemists, materials scientists and engineers, this Review focuses primarily on the physics and physical chemistry of CNC suspensions and the process of drying them. The ambition is to explain rather than to repeat, hence we spend more time than usual on the meanings and relevance of the key colloid and liquid crystal science concepts that must be mastered in order to understand the behavior of CNC suspensions, and we present some interesting analyses, arguments and data for the first time. We go through the development of cholesteric nuclei (tactoids) from the isotropic phase and their potential impact on the final dry films; the spontaneous CNC fractionation that takes place in the phase coexistence window; the kinetic arrest that sets in when the CNC mass fraction reaches ~10 wt.\%, preserving the cholesteric helical order until the film has dried; the 'coffee-ring effect' active prior to kinetic arrest, often ruining the uniformity in the produced films; and the compression of the helix during the final water evaporation, giving rise to visible structural color in the films. [less ▲]

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See detailEcrire l'histoire de la place financière d/au Luxembourg
Majerus, Benoît UL

in Marx, Claude; Limpach, Marc; Majerus, Benoît (Eds.) Surveillance, indépendance et intégrité (2020)

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See detailStadt - Land - Fluss. Grabdenkmäler der Treuerer in lokaler und überregionaler Perspektive. Akten der internationalen Konferenz 25.-27. Oktober 2018 in Neumagen und Trier
Binsfeld, Andrea UL; Klöckner, Anja; Kremer, Gabrielle et al

Book published by Dr. Ludwig Reichert Verlag (2020)

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See detailAntiferroelectricity in a family of pyroxene-like oxides with rich polymorphism
Aramberri, Hugo; Iñiguez, Jorge UL

in Communications Materials (2020)

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See detailSidelobe Performance Analysis of Noise Waveforms Considering the Doppler Mismatch
Tedgue Beltrao, Gabriel UL; Pralon, Leandro; Alaeekerahroodi, Mohammad UL et al

in Proceedings of the 21st International Radar Symposium (IRS), Warsaw, Poland, 2020 (2020)

Waveform design and optimization algorithms generally assume a zero-Doppler ideal case to reach an optimum or satisfactory solution in terms of the matched filter output. Therefore, its performance is ... [more ▼]

Waveform design and optimization algorithms generally assume a zero-Doppler ideal case to reach an optimum or satisfactory solution in terms of the matched filter output. Therefore, its performance is usually characterized only in terms of the resultant waveforms autocorrelation function, neglecting the practical situation in which the received signal is modulated by the target’s Doppler shift. Within this context, this work investigates the Doppler mismatch effects in the Integrated Sidelobe Level (ISL) performance of previously designed/optimized noise waveforms. The analysis has shown that, despite much better results for steady targets, the increasing Doppler mismatch reduces the ISL performance of optimized waveforms, until similar levels achieved when no optimization is performed. To address that, a subpulse Doppler processing approach is also considered, and the results have shown that, besides increasing the Doppler tolerance, it has also increased the optimized waveform robustness to the Doppler mismatch, reducing the resultant ISL loss and thus extending its applicability. [less ▲]

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See detailreview of Simon Maclean, Ottonian Queenship, Oxford: Oxford University Press, 2017, xiv + 247 p.; ISBN 978-0-19-880010-1: 65$
Pettiau, Hérold UL

in Hemecht: Zeitschrift für Luxemburger Geschichte (2020), 72(3), 370-373

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See detailThe Politics of Happiness in Richard Brome’s The Queen and Concubine
Steveker, Lena UL

in Critical Survey (2020), 32(3), 70-81

Drama written for the commercial stage during the 1630s has long been seen as falling neatly into two categories: the majority of plays is seen as reflecting a courtly taste for cultural escapism believed ... [more ▼]

Drama written for the commercial stage during the 1630s has long been seen as falling neatly into two categories: the majority of plays is seen as reflecting a courtly taste for cultural escapism believed to have been cultivated during a time in which the court increasingly found itself in opposition to the rest of the country. In contrast, a smaller group of plays is read as 'opposition drama' voicing thinly veiled discontent with Charles I’s personal rule. In this article, I challenge this critical dichotomy by arguing that Richard Brome’s The Queen and Concubine, written for the King’s Revels company in 1635-36, affirms notions of good government which are central to Caroline ideals of kingship. As I show, Brome’s play uses its female protagonist Eulalia, banished Queen of Sicily, in order to promote a politics of happiness that draws on the iconography of Charles I as well as on ideals of statecraft endorsed by the English king in the 1630s. [less ▲]

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See detailApproximation of Hilbert-valued Gaussians on Dirichlet structures
Bourguin, Solesne; Campese, Simon UL

in Electronic Journal of Probability (2020), 25

We introduce a framework to derive quantitative central limit theorems in the context of non-linear approximation of Gaussian random variables taking values in a separable Hilbert space. In particular ... [more ▼]

We introduce a framework to derive quantitative central limit theorems in the context of non-linear approximation of Gaussian random variables taking values in a separable Hilbert space. In particular, our method provides an alternative to the usual (non-quantitative) finite dimensional distribution convergence and tightness argument for proving functional convergence of stochastic processes. We also derive four moments bounds for Hilbert-valued random variables with possibly infinite chaos expansion, which include, as special cases, all finite-dimensional four moments results for Gaussian approximation in a diffusive context proved earlier by various authors. Our main ingredient is a combination of an infinite-dimensional version of Stein’s method as developed by Shih and the so-called Gamma calculus. As an application, rates of convergence for the functional Breuer-Major theorem are established. [less ▲]

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See detailDas Amazonenmonument. Ein frühkaiserzeitliches Grabmonument aus Arlon
Binsfeld, Andrea UL; Ruppert, Christine UL

in Stadt - Land - Fluss. Grabdenkmäler der Treuerer in lokaler und überregionaler Perspektive (2020)

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See detailManipulating magnetoelectric energy landscape in multiferroics
Huang, Yen-Lin; Nikonov, Dmitri; Addiego, Christopher et al

in Nature Communications (2020)

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See detailA three-order-parameter bistable magnetoelectric multiferroic metal
Urru, Andrea; Ricci, Francesco; Filippetti, Alessio et al

in Nature Communications (2020)

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See detailUsing cohort data to emulate lifestyle interventions: Long-term beneficial effects of initiating physical activity on cognitive decline and dementia
Leist, Anja UL; Muniz-Terrera, Graciela; Solomon, Alina

in Alzheimer's and Dementia: the Journal of the Alzheimer's Association (2020), 16

Background: Intervention studies have shown beneficial short-term effects of physical activity on cognitive decline and reduced risk of dementia. However, randomized controlled trial data of lifestyle ... [more ▼]

Background: Intervention studies have shown beneficial short-term effects of physical activity on cognitive decline and reduced risk of dementia. However, randomized controlled trial data of lifestyle interventions over long time spans are not available due to lack of resources, feasibility or ethical reasons. Drawing from the principles of emulating a ‘target trial’, which apply design principles of randomized trials to the analysis of observational data, cohort data of a large European survey were analyzed to understand the long-term effects of physical activity changes. Method: Biennial assessments of the economic, social, and health situation of respondents aged 50 and older came from the Survey of Health, Ageing and Retirement in Europe (2004-2017). Cognitive functioning (immediate recall, delayed recall, and verbal fluency) and self-reported diagnosis of dementia were assessed at each follow-up. The target trial included sedentary respondents at t1 who, at follow-up (t2), stayed sedentary (“control group”) or newly reported vigorous physical activity more often than once a week (initiators, “treatment group”). Inclusion and exclusion criteria were implemented as close as possible to those of the FINGER trial. Inverse-probability weighting accounted for the probability of initiating physical activity with a large set of predictor variables. Selecting respondents aged 50-85 years old who met the target trial inclusion and exclusion criteria, assessments of cognitive functioning and self-reported diagnosis of dementia were available for 8,781 respondents at t3 (on average 3.02 years later), 3,858 respondents at t4 (5.84 years), and 2,304 respondents at t5 (7.72 years). A total of 304 respondents reported a diagnosis of dementia. Result: Initiators of vigorous physical activity had higher cognitive functioning at two follow-ups compared to non-initiators (t3: “average treatment effect on the treated”, ATET=0.059, CI: 0.028, 0.090), which remained significant after implementing inclusion and exclusion criteria. Initiators had lower risk of dementia compared to non-initiators at all three follow-ups (t3: ATET=-0.009, CI: -0.015, -0.005, relative risk decrease -46.7%), remaining significant after implementing inclusion and exclusion criteria. Conclusion: Emulating a target trial showed long-term benefits of initiating physical activity for cognitive functioning and dementia risk. Multidomain interventions related to nutrition, social, cognitive activities etc. can be similarly emulated. [less ▲]

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See detailTelling Tales of Empire in Contemporary British Popular Culture
Steveker, Lena UL

in Habermann, Ina; Krug, Christian (Eds.) And Hereby Hangs a Tale: A Critical Anatomy of (Popular) Tales (2020)

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See detailDer Kalte Krieg und das Meer. Zur Erinnerungspolitik des U-Boot-Films
Pause, Johannes UL

in Zeitschrift für Interkulturelle Germanistik (2020), 11(2), 171-186

Military exploits in the Cold War often differed from conventional acts of war particularly in that they were, by necessity, invisible: In order to prevent nuclear conflict, crises needed to be kept ... [more ▼]

Military exploits in the Cold War often differed from conventional acts of war particularly in that they were, by necessity, invisible: In order to prevent nuclear conflict, crises needed to be kept secret, and were therefore not inscribed into cultural memory. Nuclear submarines are paradigmatic of this dynamic: As mobile nuclear missile silos, they played a central role in the balance of terror during the Cold War, effective because they remained passive and invisible. Cold War era submarine films, however, followed old genre traditions by conceiv-ing the submarine as a tactical, mostly explorative and active weapon. It was not until the 1990s that a reboot of the genre emerged, which sought to make the depths of the ocean vis-ible and memorable as a strategic location of the Cold War. Rather than portraying pure military actions, these movies tell stories of intercultural negotiation which, to prevent the outbreak of nuclear war, had to remain hidden under the surface of the sea. [less ▲]

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See detailParabolic semi-orthogonal decompositions and Kummer flat invariants of log schemes
Scherotzke, Sarah UL; Sibilla, Nicolo; Talpo, Mattia

in Documenta Mathematica (2020)

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See detailProbing Antiferroelectric-Ferroelectric Phase Transitions in PbZrO3 Capacitors by Piezoresponse Force Microscopy
Haidong Lu; Sebastjan Glinsek; Pratyush Buragohain et al

in Advanced Functional Materials (2020)

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See detailGluing semi-orthogonal decompositions
Scherotzke, Sarah UL; Sibilla, Nicolo; Talpo, Mattia

in Journal of Algebra (2020)

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See detailTopological network measures for drug repositioning.
Badkas, Apurva UL; De Landtsheer, Sébastien; Sauter, Thomas UL

in Briefings in bioinformatics (2020)

Drug repositioning has received increased attention since the past decade as several blockbuster drugs have come out of repositioning. Computational approaches are significantly contributing to these ... [more ▼]

Drug repositioning has received increased attention since the past decade as several blockbuster drugs have come out of repositioning. Computational approaches are significantly contributing to these efforts, of which, network-based methods play a key role. Various structural (topological) network measures have thereby contributed to uncovering unintuitive functional relationships and repositioning candidates in drug-disease and other networks. This review gives a broad overview of the topic, and offers perspectives on the application of topological measures for network analysis. It also discusses unexplored measures, and draws attention to a wider scope of application efforts, especially in drug repositioning. [less ▲]

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