The European Physical Journal (EPJ) is a series of peer-reviewed journals covering the whole spectrum of physics and related interdisciplinary subjects. EPJ is committed to high scientific quality in publishing and is indexed in all main citation databases.
Positive (red) and negative (blue) isosurfaces of the magnetisation density of doped zirconia
A new study discusses the electric and magnetic characteristics of a material which could be used in spintronics
Materials belonging to the family of dilute magnetic oxides (DMOs) — an oxide-based variant of the dilute magnetic semiconductors — are good candidates for spintronics applications. This is the object of study for Davide Sangalli of the Microelectronics and Microsystems Institute (IMM) at the National Research Council (CNR), in Agrate Brianza, Italy, and colleagues. They recently explored the effect of iron (Fe) doping on thin films of a material called zirconia (ZrO2 oxide). For the first time, the authors bridged the gap between the theoretical predictions and the experimental measurements of this material, in a paper just published in EPJ B.
Physicists are providing an all-in-one guide to help calculate the effect the use of optical tweezers has on the energy levels of atoms under study
A small piece of paper sticks to an electrically charged plastic ruler. The principle of this simple classroom physics experiment is applied at the microscopic scale by so-called optical tweezers to get the likes of polystyrene micro-beads and even living cells to “stick” to a laser beam, or to trap atoms at ultra-low temperatures. Physicist Fam Le Kien and his colleagues from the Institute of Atomic and Subatomic Physics of the Vienna University of Technology, Austria, provide a comprehensive manual with general theoretical tools, definitions, and spectroscopic data sets for calculating the energy levels of atoms, which are modified by light emanating from optical tweezers, in a study just published in EPJ D.
The publishers of EPJ are pleased to announce the launch of a new Open Access journal: EPJ Nonlinear Biomedical Physics. A Commentary and two Research papers are already available.
This new peer-reviewed journal will promote and disseminate new research in the field of quantitative biomedical complexity science. Its special focus is on the applications of nonlinear dynamics and complexity-inspired integrative systems science, to the quantitative modeling and understanding of how structure, function and/or dysfunctions and diseases emerge in complex biomedical matter, systems and processes.
Set of measured velocity profiles with Carbopol microgel.
A new study explores the counter-intuitive behaviour of a microgel composed of soft polymer blobs
Being a physicist offers many perks. For one, it allows an understanding of the substances ubiquitous in everyday industrial products such as emulsions, gels, granular pastes or foams. These are known for their intermediate behaviour between fluid and solid. Paint, for example, can be picked up on a paintbrush without flowing and spread under the stress of the brush stroke like a fluid. Baudouin Geraud and colleagues from the Light Matter Institute at the University of Lyon, France, have studied the flow of a microgel confined in microchannels. They have shown, in a study just published in EPJ E, that its behaviour under confinement differs from predictions based on standard theories. Indeed, its molecules are not only subjected to local forces, but also to neighbouring forces that affect its flow.
EPJ Plus welcomes Eugenio Nappi as co-Editor in Chief, alongside Luisa Cifarelli. Nappi is Director of Research at INFN, the Italian Istituto Nazionale di Fisica Nucleare. He is an experimental particle physicist who has carried out most of his research activities at CERN and DESY.
His main research interests include the study of heavy nucleus collisions at ultrarelativistic energies with the ALICE Experiment at LHC, where he held the highest managerial positions. In 2000, he became project leader of the Cherenkov system, named HMPID, the largest CsI Ring Imaging Cherenkov (RICH) detector ever built. In the same year he joined the HERMES experiment at HERA-DESY. In HERMES, he spearheaded the design of the first-ever aerogel radiator RICH detector. More recently, he has become interested in medical imaging and joined the AXPET collaboration at CERN, which is intended to develop a new concept for Positron Emission Tomography (PET).
Author of more than 250 peer-reviewed papers, he is a member of the
Executive Board of INFN, the ICFA Panel on Instrumentation, the CST of CNRS-IPN Orsay, the ECE (Expert Committee for the Experiments) of FAIR and the STC (Steering Committee) OF ESS (European Spallation Source).
Earlier this year Francesco Guerra, who had been a member of the editorial board of EPJ H - Historical Perspectives on Contemporary Physics since its launch in 2010, joined Wolf Beiglböck in managing the journal.
Prof. Francesco Guerra, a graduate from the University of Naples, is full professor of theoretical physics at the University of Rome 'La Sapienza'. He has served on many national academic evaluation committees and is currently a member of the Physics Panel of the National Agency for the Evaluation of Universities and Research.
His scientific interests include quantum field theory and elementary particles, stochastic methods in quantum mechanics, stochastic variational principles, statistical mechanics of spin glasses and complex systems, and the history of modern physics (in particular nuclear physics). In 2008, he was the recipient of the Italian Physical Society’s Prize for History of Physics.
EPJE is inviting submission for a new topical issue on “Thermal non-equilibrium phenomena in multi-component fluids”. Under thermal non-equilibrium conditions, multi-component fluids generally undergo component separation. This is termed thermodiffusion in molecular liquids, and thermophoresis in colloidal fluids. The precise physical principles underlying these phenomena are still not understood, and it is envisaged that a continuous flow of ideas between theoreticians, experimental scientists and researchers employing numerical methods is needed to achieve a deeper understanding. In order to provide an overview of the more recent advances in this intriguing area, Fabrizio Croccolo and Henri Bataller will guest edit this topical issue on physical systems outside thermal equilibrium. The deadline for submission is 30 June 2014. Read the full call for papers to learn more about the scope and submission details.
Studying the effect of migration on cooperation could help to better understand social cohesion
Migrations happen for a reason, not randomly. A new study, based on computer simulation, attempts to explain the effect of so-called directional migration – migration for a reason – on cooperative behaviours and social cohesion. These results appear in a study just published in EPJ B by Hongyan Cheng from Beijing University of Posts and Telecommunications and colleagues.
New research shows that the speed of light may not be fixed after all, but rather fluctuates
Two EPJ D papers challenge established wisdom about the nature of vacuum. In one paper, Marcel Urban from the University of Paris-Sud, located in Orsay, France and his colleagues identified a quantum level mechanism for interpreting vacuum as being filled with pairs of virtual particles with fluctuating energy values. As a result, the inherent characteristics of vacuum, like the speed of light, may not be a constant after all, but fluctuate. Meanwhile, in another study, Gerd Leuchs and Luis L. Sánchez-Soto, from the Max Planck Institute for the Physics of Light in Erlangen, Germany, suggest that physical constants, such as the speed of light and the so-called impedance of free space, are indications of the total number of elementary particles in nature.
Scientists have accurately calculated the sliding mechanism for deciphering the second genetic code written within the DNA base pair sequence
Three-quarters of the DNA in evolved organisms is wrapped around proteins, forming the basic unit of DNA packaging called nucleosomes, like a thread around a spool. The problem lies in understanding how DNA can then be read by such proteins. Now, Arman Fathizadeh, a physicist at Sharif University of Technology in Tehran, Iran, and colleagues have created a model showing how proteins move along DNA, in a paper just published in EPJ E.
A new study of animal swarms uncovers some new features of their collective behaviour when overcrowding sets in
Swarming is the spontaneous organised motion of a large number of individuals. It is observed at all scales, from bacterial colonies, slime moulds and groups of insects to shoals of fish, flocks of birds and animal herds. Now physicists Maksym Romenskyy and Vladimir Lobaskin from University College Dublin, Ireland, have uncovered new collective properties of swarm dynamics in a study just published in EPJ B. Ultimately, this could be used to control swarms of animals, robots, or human crowds by applying signals capable of emulating the underlying interaction of individuals within the swarm, which could lead to predicted motion patterns elucidated through modelling.
Numerical simulation by Paul Manneville of plane Couette flow showing the coexistence of turbulent and laminar bands.
EPJE is now accepting submissions for a topical issue on “irreversible dynamics”, dedicated to Paul Manneville. The study of classical physics underwent a revolution in the 1970s-1980s thanks to seminal contributions by Ruelle, Takens, Pomeau and Manneville. The concurrent revival and extension of the theory of dynamical systems encompasses spatiotemporal chaos and coupled oscillator arrays. Applications to fluid dynamics range from pattern formation in convection, to the onset of turbulence in shear flows. The concurrent revival and extension of the theory of dynamical systems encompasses spatiotemporal chaos and coupled oscillator arrays. Applications to fluid dynamics range from pattern formation in convection, to the onset of turbulence in shear flows. Laurette Tuckerman or Patrice Le Gal, Guest Editors of this topical issue, extend a warm invitation to all researchers, with a wide interpretation of the field. The deadline for submission is July 1st 2013. The full call for papers can be found here
Experience gained from data sharing during the human genome sequencing project could apply to the broader research community
In a paper about to be published in EPJ Data Science, Barbara Jasny, deputy editor for commentary at Science magazine in Washington, DC, USA, looks at the history of the debates surrounding data access during and after the human genome “war”. In this context, she outlines current challenges in accessing information affecting research, particularly with regard to the social sciences, personalised medicine and sustainability.
Work on a high-conductivity material demonstrates the role of oxygen ions in enhancing their capabilities
Yttria stabilized zirconia, also known as YSZ, is a material of great interest because of its relatively high oxygen-ion based conductivity. In particular, it finds applications in electrochemical devices, such as solid oxide fuel cells and oxygen sensors. In a study published in EPJ B, Kia Ngai, from the University of Pisa in Italy, and colleagues from the Complutense University in Madrid, Spain, devised a model of the oxygen-ion dynamics that contribute to the conductivity of YSZ.
The unexpected diversity of metallic nanoclusters’ inner structure has now been catalogued into families
Physicists have gained new insights into the inner intricacies of the structural variations of metallic nanoclusters. This work by Luca Pavan, Cono Di Paola and Francesca Baletto from King's College London, UK, has just been published in EPJ D. It takes us one step closer to tailoring on-demand characteristics of metallic nanoparticles. Indeed, the geometric structure of these nanoclusters influences their chemical and physical properties, which differ from those of individual molecules and of bulk metals.
A new approach is available for real-time monitoring of the structural health of wind turbine components during exposure to turbulences.
Physicists have now developed a new method for analysing the elastic characteristics of mechanical structures subjected to disturbances, akin to the turbulences affecting wind turbines. These results have just been published in EPJ B by Philip Rinn and his colleagues at the ForWind Center for Wind Energy Research at the University of Oldenburg, Germany.
A significant percentage of the costs of wind energy is due to wind turbine failures, as components are weakened under turbulent air flow conditions and need to be replaced. The challenge for the team was to find a method for detecting fatigue in the wind turbines’ parts without having to remove each of the components and while the turbine is in operation.
A new algorithm could help understand the structure of liquids, and how they flow through porous media
Theoretical physicist Moumita Maiti and colleagues at the Jawaharlal Nehru Centre for Advanced Scientific Research in Bangalore, India, have now implemented an algorithm for analysing void space in sphere packing, where the spheres need not all be the same size. This method, just published in EPJ E, could be applied to analyse the geometry of liquids present between multi-sized spheres that are akin to a model for porous material. This provides a tool for studying the flow of such fluids through porous material. More importantly, it can also be used to study the packing geometry of proteins.
What can go wrong when computer simulations are applied outside their original context
In an article just published in EPJ Plus, Daan Frenkel from the University of Cambridge, UK, outlines the many pitfalls associated with simulation methods such as Monte Carlo algorithms or other commonly used molecular dynamics approaches.
The context of this paper is the exponential development of computing power in the past 60 years, estimated to have increased by a factor of 1015, in line with Moore’s law. Today, short simulations can reproduce a system the size of a bacterium.
Varying magnetic fields and temperature conditions help to elucidate smart materials’ transitory magnetic disorder
Novel, smart materials like shape memory alloys very often display so-called glass-like magnetism. Other smart materials with similar properties include those which, when exposed to a magnetic field, change their electrical resistance, known as manganites, or change their temperature, known as magnetocaloric materials. Kaustav Mukherjee and his colleagues from the Consortium for Scientific Research Indore in India studied a key stage in the formation of such a magnetic glass material, called Pr0.5 Ca0.5 Mn0.975 Al0.025 O3, in a paper just published in EPJ B.
From January 2013 Vladimir Bužek succeeds Claude Fabre as Editor in Chief of EPJ D with responsibility for papers in quantum optics, quantum information and related topics.
Prof. Dr. Bužek graduated from the Moscow State University (both MSc and PhD) in theoretical physics. His research interests are focused on quantum optics, quantum information sciences, quantum measurement theory and foundations of quantum mechanics. He has been the head of the Research Center for Quantum Information at the Slovak Academy of Sciences and holds a professorial position at the Faculty of Informatics of the Masaryk University in Brno, Czech Republic.
Friedrich Hasenöhrl found proportionality between energy and its mass in a cavity filled with radiation. Source: Österreichische Zentralbibliothek fuer Physik
A new study reveals the contribution of a little known Austrian physicist, Friedrich Hasenöhrl, to uncovering a precursor to Einstein famous equation
An American physicist outlines the role played by Austrian physicist Friedrich Hasenöhrl in establishing the proportionality between the energy (E) of a quantity of matter with its mass (m) in a cavity filled with radiation. In a paper just published in EPJ H, Stephen Boughn from Haverford College in Pensylvannia argues how Hasenöhrl’s work, for which he now receives little credit, may have contributed to the famous equation E=mc2.
Scientists have unearthed a new dynamic process induced by strong electric fields in thin liquid crystal cells
Liquid crystal displays are ubiquitous. Now, Polish physicists have demonstrated that the application of a very strong alternating electric field to thin liquid crystal cells leads to a new distinct dynamic effect in the response of the cells. The theory of spatio-temporal chaos explains this effect. It was elucidated by Wojciech Jeżewski and colleagues from the Institute of Molecular Physics, Polish Academy of Sciences, in Poznań, Poland, and was just published in EPJ E. This effect has implications for the operation of liquid-crystal devices because their operation is based on the electro-optic switching phenomenon, subject to the newly discovered effect.
EPJ Web of Conferences is now indexed in Scopus, the world’s largest abstract and citation database of research literature. Scopus covers more than 20,500 titles from over 5,000 international publishers, in the scientific, technical, medical, and social sciences.
Understanding the mechanisms of electron-molecule collisions could help predict the operations inside the fusion chamber of the ITER reactor
An international team of physicists has calculated the efficiency of a reaction involving an incoming electron kicking out an electron from the metal beryllium (Be) or its hydrogen compound molecules, in an article just published in EPJ D. The efficiency, which partly depends on the electron’s incoming speed, is encapsulated in a quantity referred to as electron-impact ionisation cross sections (EICS). Electron-molecule interactions matter because they occur in a broad range of applications from the simplest like fluorescent lamps to the most complex, for example, in ionised matter found in plasmas such as latest generation screens, the outer space of the universe, and in fusion reactors.
From January 2013 Nicolas Alamanos succeeds Enzo De Sanctis as Editor in Chief of EPJ A for the experimental physics section.
Professor Alamanos is Deputy Director of the Institute of Research into the Fundamental Laws of the Universe (IRFU) and Research Director at CEA Saclay working in the domain of fundamental research in Nuclear Physics. During his long scientific career, he has served on many scientific and program advisory committees and has occupied different managerial positions. Most notably he has been president of GANIL’s scientific council and director of Saclay Nuclear Physics Division. He is a member or evaluator of many national committees – ARISTEIA (GRECE), FRS-FNRS (Belgium), ANR (France). He is currently a member of the GANIL/SPIRAL2 scientific council, of GANIL’s program advisory committee, and scientific counselor of the European program “CEA-Euro talents” in the domain of high energy physics and physics of the universe.
In addition to his various scientific and administrative duties, Professor Alamanos has always been very active editorially: beyond having been a member of the editorial board of EPJ A for many years, he is the Editor of the Scholarpedia Encyclopedia of Nuclear Physics.
New models suggest devising means of probing a surface at a sub-micrometric level as this will help us understand how electrons’ diffusion affects long-range attractive forces
Theoretical physicist Elad Eizner from Ben Gurion University, Israel, and colleagues created models to study the attractive forces affecting atoms located at a wide range of distances from a surface, in the hundreds of nanometers range. Their results, just published in EPJ D, show that these forces depend on electron diffusion, regardless of whether the surface is conducting or not. Ultimately, these findings could contribute to designing minimally invasive surface probes.
By doping a bismuth-based layered material with silver, Chinese scientists demonstrated that superconductivity is intrinsic to the new material rather than stemming from its impurities
The first report on the chemical substitution, or doping, using silver atoms, for a new class of superconductor that was only discovered this year, has just been published in EPJ B. Chinese scientists from Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, discovered that the superconductivity is intrinsic rather than created by impurities in this material with a sandwich-style layered structure made of bismuth oxysulphide (Bi4O4S3).
A new model could ultimately help robotic fingers, made of a soft surface, manipulate small objects
Imagine a solid ball rolling down a slightly inclined ramp. What could be perceived as child’s play is the focus of serious theoretical research by Manoj Chaudhury and Partho Goohpattader, two physicists from Lehigh University, Bethlehem, Pensylvania, USA. Their study, which has just been published in EPJ E, has one thing in common with childhood behaviour. It introduces a mischievous idea, namely studying the effect of random noise, such as vibrations, on the ball. They found it could lower the energy barrier to set the ball in motion.
Physicists and biologists apply Big Data statistical tools to study marine plant evolution
A new method that could give a deeper insight into evolutional biology by tracing directionality in gene migration has just appeared in EPJ Data Science. Paolo Masucci from the Centre for Advanced Spatial Analysis, at University College of London, UK, and colleagues identified the segregation of genes that a marine plant underwent during its evolution. They found that the exchange of genes, or gene flow, between populations of a marine plant went westward from the Mediterranean to the Atlantic. This methodology could also be used to estimate the information flow in complex networks, including other biological or social networks.
The origin of ultra-high-energy cosmic rays, with energies around the GZK cutoff, remains an unsolved mystery. In the present letter a novel and intriguing explanation is suggested that links far-reaching fundamental aspects of F(R) modified theories to an efficient production of highly energetic cosmic rays during the recent history of the Universe.
At the core of this work lies the proof that in cosmological and astrophysical systems with rising energy densities, the F(R) modified theories of gravity exhibit powerful oscillations of the curvature scalar R, with an amplitude much larger than the standard value of curvature predicted by the General Relativity. These oscillations are strongly anharmonic, with frequencies that can be as large as billions of GeV. This striking and rather unexpected oscillatory behavior of R lends support to the idea that ultra-high energy cosmic rays can be generated by such curvature oscillations at the appropriate cosmological redshifts.