News / Highlights / Colloquium
EPJ ST Highlight - Dynamics of the COVID-19 pandemic
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- Published on 13 January 2023

The outbreak of COVID-19 changed the human perception of day-to-day life and tested the bounds of medical technology in protecting the welfare of humans. Several approaches and safety measures have been implemented to minimize the countless lives that are being affected. However, public health and educational breaches are evidenced in most countries in which not all citizens have the same opportunities to deal with the pandemic. Therefore, this has led to pervasive consequences, including mental health problems because of the disruption of everyday life routines.
This special issue is a collection of 35 orginal research articles that address the dynamics and applications of COVID-19 through nonlinear dynamics. The articles are organized in five sections, comprising mathematical modeling and epidemics, the dynamics of several waves and transmission, neural network and deep learning related to COVID-19, predictions and estimations related to COVID-19, and detailed analysis on the pandemic and its applications. The various contributions report important, timely, and promising results and provide insight into the spread of the coronavirus and control measures against the COVID-19 pandemic.
All articles are available here and are freely accessible until 21 March 2023. For further information read the Editorial by Santo Banerjee ”Dynamics of the COVID-19 pandemic: nonlinear approaches on the modelling, prediction and control” Eur. Phys. J. Spec. Top. 231, 3275–3280 (2022). https://doi.org/10.1140/epjs/s11734-022-00724-1
EPJ ST Highlight - Showcasing the possibilities of memristor circuits
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- Published on 13 January 2023

The papers presented in this special issue explore several unique capabilities of memristor-based systems: including multistability, nonlinearity, and chaotic dynamics
First demonstrated in 2008, the memristor is an electrical component which can limit the amount of current in a circuit, while remembering the amount of charge it conveyed in the past. Yet despite its numerous potential applications, the memristor’s commercial rollout has so far been restricted by the high manufacturing costs of its nano-scale electrical components.
To improve both the range of applications and theoretical understanding of memristors, there is a need to investigate their fundamental features, while diversifying the tools used to model their behaviours. In this special issue, the journal EPJ ST presents 25 new papers showcasing the widely-varied possibilities by memristor systems, and the mathematical principles required to understand and model them.
EPJ ST Editor Peter Hänggi awarded 2023 APS Lars Onsager Prize
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- Published on 28 November 2022

The American Physical Society awards the prestigious Lars Onsager Prize every year to one or several individuals for outstanding research in theoretical statistical physics including the quantum fluids. Professor Peter Hänggi, Universität Augsburg, Germany, Editor of EPJ ST, former Editor-in-Chief of EPJ B and 2007 Chairperson of the EPJ Scientific Advisory Committee receives the 2023 APS Lars Onsager Prize "for the development of Brownian motors and pioneering contributions to nonequilibrium statistical physics, relativistic and quantum thermodynamics."
EPJ ST Highlight - Elastic nozzles could create more stable liquid jets
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- Published on 27 September 2022

New experiments show that nozzles which deform as liquid flows through them could help to improve the stability of liquid jets in many different scenarios
When a liquid jet is squirted through a nozzle, it will eventually break up into a string of droplets. Through previous studies, researchers determined that the distance from the nozzle where this breakup occurs depends on a wide range of factors: including the nozzle’s shape, and the movement of air surrounding the jet. So far, however, little attention has been paid to elastic nozzles, which can deform as liquids pass through them. Through new research published in EPJ ST, a team led by Andrew Dickerson at the University of Tennessee, USA, introduces the concept of passively-deforming nozzles, and shows that softer nozzle materials can produce more stable jets across a wide range of flow rates.
EPJ ST Highlight - Tiny animal hairs could act as sensitive compass needles
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- Published on 20 September 2022

Statistical mechanics shows that some animals may be able to perceive Earth’s magnetic field with bundles of microscopic hairs in their inner ears.
The exact mechanisms animals use to sense the direction of Earth’s magnetic field have long remained a mystery. One leading theory suggests that this ability is tied to bundles of microscopic hair cells in the inner ears. Through new research published in EPJ ST, Kirill Kavokin at St Petersburg State University, Russia, uses statistical analysis to show that just around 100 of these hair cells could act as effective biological compass needles, allowing animals to accurately sense the magnetic field surrounding them.
EPJ ST Highlight - Chaotic circuit exhibits unprecedented equilibrium properties
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- Published on 26 July 2022

Mathematical derivations have unveiled a chaotic, memristor-based circuit in which different oscillating phases can co-exist along 6 possible lines.
Unlike ordinary electronic circuits, chaotic circuits can produce oscillating electrical signals which never repeat over time – but nonetheless, display underlying mathematical patterns. To expand the potential applications of these circuits, previous studies have designed systems in which multiple oscillating phases can co-exist along mathematically-defined ‘lines of equilibrium.’ In new research published in EPJ ST, a team led by Janarthanan Ramadoss at the Chennai Institute of Technology, India, designed a chaotic circuit with six distinct lines of equilibrium – more than have ever been demonstrated previously.
EPJ ST Highlight - The fascinating ways animals navigate
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- Published on 30 June 2022

Many animals – from birds to whales to zebras – find their way across great distances using a variety of environmental factors.
The Arctic Tern migrates an extraordinarily long way – from pole to pole. And while this bird is unique in the distance it traverses, its excellent sense of direction is shared by many other animals that use a variety of environmental factors to optimise their routes. In a new review paper in EPJ ST, Roswitha and Wolfgang Wiltschko from the Goethe-Universität in Frankfurt am Main, Germany, outline how animals use internal compasses to navigate and the mechanisms they are likely to use to determine the direction of their destination. These can be applied when developing effective navigation systems for robots.
EPJ ST: Franck Lépine new Editor on board
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- Published on 24 June 2022

The publishers of The European Physical Journal Special Topics are pleased to announce the appointment of Dr. Franck Lépine as new Editor in the board.
Franck Lépine is a CNRS research director at ILM (France) where he leads, since 2013, a pluridisciplinary group working on the "structure and dynamics of molecules". His current field of interest is attosecond science.
After a PhD in physics concerning "imaging atomic wavefunction and understanding the concept of temperature in small atomic clusters", Franck Lépine joined the FOM-AMOLF institute where he worked on ultrafast dynamics and the emerging field of attosecond physics. In 2005 He joined CNRS in Lyon and developed a research program on photoionization and ultrafast attosecond dynamics in complex molecules. He was involved in the development of the ELI-ALPS institute (Hungary), where he led the "strong field and attosecond physics" department.
Since 2016, he is the director of the French Network for ultrafast science (GDR UP) that brings together the French community interested in ultrafast phenomena. He co-authored more than 100 peer-reviewed articles, including several review articles in the field of attosecond science.
EPJ ST Highlight - How can x-ray diffraction be used for a reliable study of nanostructured materials?
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- Published on 13 June 2022

A new overview shows how x-ray diffraction can effectively measure lattice defects responsible for the unique properties of nanostructured materials – but special care is required for the application
Owing to their unique physical properties, nanostructured materials are now at the forefront of materials science. Several different techniques can be used to characterise their microscopic features, but each of these has its pros and cons. In new research published in EPJ ST, Jenő Gubicza at ELTE Eötvös Loránd University, Budapest, shows that one indirect method, named x-ray diffraction line profile analysis (XLPA) is suitable for analysing nanostructured materials, but its application and interpretation require special care for obtaining reliable conclusions.
EPJ ST Highlight - Energy harvesting to power the Internet of Things
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- Published on 09 June 2022

A new paper in EPJ Special Topics shows how energy can be harvested from vibrating micromagnets to power the now ubiquitous wireless sensors in the most efficient way.
The wireless interconnection of everyday objects known as the Internet of Things depends on wireless sensor networks that need a low but constant supply of electrical energy. This can be provided by electromagnetic energy harvesters that generate electricity directly from the environment. Lise-Marie Lacroix from the Université de Toulouse, France, with colleagues from Toulouse, Grenoble and Atlanta, Georgia, USA, has used a mathematical technique, finite element simulation, to optimise the design of one such energy harvester so that it generates electricity as efficiently as possible. This work has now been published in EPJ ST.