News

EPJ B Highlight - Simulating better performance in piezoelectric energy harvesters

Modelling Lévy noise for a piezoelectric energy harvester

Analysis explains how nonlinear piezoelectric devices are far better than their linear counterparts at harvesting energy from noisy vibrations across a broad range of frequencies

Over the past few decades, the capabilities of piezoelectric energy harvesters have steadily improved, paving the way for micro- and nano-electronic devices which can be powered directly from the energy of ambient, noisy vibrations in their surrounding environments. So far, however, these devices have only been able to harvest from vibrations within a narrow frequency range, severely limiting their performance in real-world scenarios.

Through new analysis published in EPJ B, Martín Giuliano and Alejandro Sánchez at the National University of Mar del Plata, Argentina, show how this performance could be improved by integrating nonlinear dynamics into piezoelectric energy harvesters – allowing them to capture the inherently broad spectrum of frequencies associated with noisy vibrations. The duo’s findings could help guide the development of next-generation energy harvesters, making them far more autonomous than existing designs.

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EPJ Plus Highlight - An interferometric approach to multi-parameter measurement

Interferometer setup for detecting multiple parameters

Novel interferometer setup enables multiple parameters of an optical network to be measured simultaneously, with a precision limited only by the laws of quantum mechanics

Quantum mechanics has vastly improved our ability to make precise measurements. By harnessing effects such as entanglement, squeezing and interference, researchers have surpassed the noise limits imposed on classical techniques – allowing for higher-resolution measurements of quantities including energy, time, and polarization. Over the past decade, it has become especially important for researchers to measure multiple physical parameters of a quantum system simultaneously. However, previous approaches have faced numerous challenges – including the constraints they impose on the values of unknown parameters.

Through new research published in EPJ Plus, an international team from the University of Bari, Italy, and the University of Portsmouth, UK, presents an interferometry-based quantum sensing scheme capable of simultaneously estimating multiple parameters of an optical network, with a sensitivity limited only by the fundamental laws of quantum mechanics. Their approach could help to improve the precision and scope of quantum measurements across applications ranging from biological imaging to gravitational wave detection.

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EPJ Plus Highlight - Probing quantum weirdness using particle colliders

Solving Bell nonlocality using collision data

An international collaboration of researchers presents a roadmap of future experiments at colliders like the LHC, investigating the nature of quantum correlations, such as entanglement and Bell nonlocality at ultra-high energies

So far, many of the most mind-bending properties of quantum mechanics have only been studied extensively in low-energy laboratory setups. Recently, however, researchers have begun to consider how these experiments could be carried out at higher energies – achievable through particle accelerators like the Large Hadron Collider (LHC). Offering energies some 12 orders of magnitude higher than lab setups, these instruments provide a novel environment where quantum phenomena can be probed experimentally.

Through a new paper published in EPJ Plus, an international collaboration of researchers presents a roadmap for these studies: identifying the challenges that need to be overcome, and setting out realistic goals for future research, which may be carried out in different scenarios at future generations of colliders. The team’s analysis could help guide efforts to deepen our understanding of the enigmatic nature of quantum mechanics.

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EPJ B Highlight - Calculating the impact of domain walls on systems’ free energies

Introducing domain walls to the Ising model

Mathematical approach improves calculations of how phase boundaries affect a material’s properties

The behaviours of many materials are strongly influenced by abrupt boundaries between different phases, called domain walls. In particular, the patterns in which domain walls arrange themselves are closely connected to a material’s free energy: a temperature-dependent quantity representing the balance between a system’s tendency toward low energy and high entropy.

Through new analysis published in EPJ B, a collaboration of European researchers have developed and applied a method that accounts for all possible arrangements of domain walls within a model system. By providing a robust approach for calculating its free energy, including finite-size effects, their method could help improve models of a wide array of structures where domain walls play a key role.

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EPJ D Highlight - Towards better neutral beam measurements for fusion reactors

Force probe for measuring neutral ion beams

New experiments show how a force probe can accurately track neutral particle beams, helping to improve fusion plasma stability

Neutral beam injection (NBI) is a valuable method for heating plasma inside a nuclear fusion reactor, and could be key to the success of upcoming projects including ITER. For the technique to work, however, the energy imparted by particle beams must be measured as accurately as possible. While ion beams can be tracked directly by their electric currents, chargeless neutral particles require more elaborate approaches – such as calorimetric profiling, spectroscopy, ionization-based methods.

In a new study published in EPJ D, researchers led by Thomas Trottenberg at Christian-Albrechts-University of Kiel, Germany, present a method to measure neutral beams using a device called a ‘force probe’, which directly measures the momentum transferred to a target. With initial measurements closely matching theoretical predictions, the demonstration could be an important step toward realizing nuclear fusion’s potential.

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EPJ Web of Conferences Highlight - CHEP2024: Computing in High Energy and Nuclear Physics

CHEP 2024 group photo in Krakow, Poland.

The 27th International Conference on Computing in High Energy and Nuclear Physics (CHEP), organized by AGH University, Henryk Niewodniczanski Institute of Nuclear Physics – Polish Academy of Sciences and Jagiellonian University, took place in Krakow, from 19–25 October 2024. The conference hosted roughly 550 registered participants from 33 different countries and 166 institutions.

The CHEP conference series began in 1985, and has grown to become the largest of its kind, providing the unique opportunity for computing experts across particle and nuclear physics to come together and learn from each other. The focus of the CHEP conference evolves along with the ever-changing technologies and major scientific initiatives.

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EPJ B Topical Issue - Recent Advances in Complex Systems

Guest Editors: Thiago B. Murari, Marcelo A. Moret, Hernane B. de B. Pereira, Tarcísio M. Rocha Filho, José F. F. Mendes, Tiziana Di Matteo

Inspired by the Conference on Complex Systems 2023 (CCS2023) in Salvador, Brazil, this collection of EPJ B brings together 25 peer-reviewed articles covering a wide range of topics.
This collection highlights the interdisciplinary nature of the field, with contributions from physics, biology, economics, linguistics, and artificial intelligence, and serves as a reference for researchers addressing real-world challenges through systems-based thinking.

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EPJ ST Highlight - A new Olympiad problem: Introducing students to a key challenge in hydroelectric power

Pelton turbine driven by a hydraulic jump

Three-part problem enables gifted high-school students to delve deeply into the physics of hydraulic jumps and their application in hydroelectric power plants to extract energy from flowing water

Olympiads are an excellent way to fuel students’ curiosity. By enabling them to apply their skills to highly relevant, real-world problems, these competitions can be a valuable way to train future generations of researchers. For now, however, Olympiad-style problems are still relatively new in physics and engineering – making it important to design questions that challenge gifted students, while staying closely tied to real-world applications.

In a study published in EPJ Special Topics (EPJ ST), Diana-Stefania Catana at the University of Bucharest presents a new Olympiad-level problem. It focuses on the physics and engineering principles underlying hydroelectric turbines, asking students to calculate their energy yields and consider their sustainability in real-world conditions.

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EPJ E Highlight - Measuring how tumours respond to compressive stress

Changing patterns in cell division and migration

Experiment improves our understanding of how compressive stress is linked to changes in how cancer cells grow and move

While a tumour’s development is strongly tied to genetic factors, these are also intertwined with physical and chemical changes in its cells. Many of these changes are linked to compressive stress, which builds up inside a growing tumour as it pushes against surrounding tissues. However, researchers still have much to learn about how these interconnected processes respond to varying levels of stress.

Through a new experiment detailed in EPJ E Morgan Delarue and colleagues at the University of Toulouse have gained deeper insights into the impact of compressive stress on the division and movement of tumour cells. Their results could help improve our understanding of tumour development – potentially opening new routes to effective cancer treatments.

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EPJ Plus Highlight - A roadmap for radiobiology and cancer research at the Extreme Light Infrastructure

Facilities of the ELI

Roadmap suggests how promising advances could be made through tightly focused and coordinated experiments at the Extreme Light Infrastructure’s facilities, combined with ongoing improvements to its instruments and infrastructure

The Extreme Light Infrastructure (ELI) is an international research organisation hosting the world’s largest collection of high-power lasers. With state-of-the-art facilities in the Czech Republic, Hungary, and Romania, it specialises in producing radiation by accelerating tightly packed bunches of subatomic particles close to the speed of light, using ultrahigh-intensity laser pulses. Among ELI’s central goals is to provide leading researchers with open access to ultra-short pulses of radiation, which are playing an increasingly important role in radiobiology and cancer therapy.

In a new paper in EPJ Plus, a collaboration led by Daniele Margarone at the ELI Beamlines Facility present a detailed roadmap for future research at ELI. Their efforts could be crucial in validating the potential of its cutting-edge radiation sources and could pave the way for transformational advances in radiobiology and cancer therapy.

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