- Published on 22 August 2018
The drying of complex solutions, such as colloidal dispersions, is a phenomenon of great interest, both scientific and technical, ranging from functional coatings, food science, cosmetology, medical diagnostics and forensics to geophysics and art. This EPJ E Colloquium discusses a wide variety of problems related to the drying of colloidal systems, from the stabilization of dairy products to cracking phenomena that occur at the surface of planets or on an oil painting. The diversity of these processes lies in the great variability in size and/or time scales and makes it very hard to understand and analyse the mechanisms at play. The results presented in this review attest to the reliability of experimental modelling in the laboratory, a clever way to use the drying of complex fluids to reproduce and study original mechanisms.
- Published on 20 August 2018
Natural switching of DNA and RNA polarisation opens possibilities to develop novel biosensors and high-capacity data storage
DNA and RNA are naturally polarised molecules containing electric dipole moments due to the presence of a significant number of charged atoms at neutral pH. Scientists believe that these molecules have an in-built polarity that can be reoriented or reversed fully or in part under an electric field—a property referred to as bioferroelectricity. However, the mechanism of these properties remains unclear. In a new study published in EPJ E, See-Chuan Yam from the University of Malaya, Kuala Lumpur, Malaysia, and colleagues show that all the DNA and RNA building blocks, or nucleobases, exhibit a non-zero polarisation in the presence of polar atoms or molecules such as amidogen and carbonyl. They have two stable states, indicating that DNA and RNA basically have memory properties, just like a ferroelectric or ferromagnetic material. This is relevant for finding better ways of storing data in DNA and RNA because they have a high capacity for storage and offer a stable storage medium. Such physical properties may play an important role in biological processes and functions. Specifically, these properties could also be extremely useful for possible applications as a biosensor to detect DNA damage and mutation.
EPJ Plus Focus Point - Modelling Complex Real-World Problems with Fractal and New Trends of Fractional Differentiation
- Published on 14 August 2018
Differential operators with non-singular kernels have been suggested recently and have raised interest in many fields of science, technology and engineering. They have being recognized to have brought news tools in applied mathematics and other applied sciences, as they are able to capture and observe a more complex physical behavior of nature. One of their unique properties is crossover behavior; in particular, their ability to capture Brownian motion, stochastic processes, anomalous diffusion and power-law dependency processes. This Focus Point on Modelling Complex Real-World Problems with Fractal and New Trends of Fractional Differentiation edited by A. Atangana, Z. Hammouch, G. Mophou and K. M. Owolabi in EPJ Plus aims at capturing current developments and initiatives of these new mathematical tools in modeling real-world problems. It focuses on new numerical and analytical methods for solving the complex real-world problems arising in physics. Several new results were presented and published in this Focus Point. In particular, a revolutionary paper has led to the extension of the field of non-local operators and their applications. The particular attention devoted to these new mathematical tools leaves no doubt on the fact that the future of modeling real-worl problems relies on these operators.
- Published on 31 July 2018
Physicists develop improved algorithms for simulating how complex molecules respond to excitation by photons, and explaining what happens when photons hit our eyes
What makes it possible for our eyes to see? It stems from a reaction that occurs when photons come into contact with a protein in our eyes, called rhodopsin, which adsorbs the photons making up light. In a paper published in EPJ B, Federica Agostini, University Paris-Sud, Orsay, France, and colleagues propose a refined approximation of the equation that describes the effect of this photo-excitation on the building blocks of molecules. Their findings also have implications for other molecules, such as azobenzene, a chemical used in dyes. The incoming photon triggers certain reactions, which can result, over time, in dramatic changes in the properties of the molecule itself. This study was included in a special anniversary issue of EPJB in honour of Hardy Gross.
- Published on 24 July 2018
Dr Valerio Lucarini, professor of Statistical Mechanics at the Department of Mathematics and Statistics, Reading https://www.reading.ac.uk/maths-and-stats/, and director of the Mathematics for Planet Earth Centre https://www.reading.ac.uk/maths-and-stats/research/mathematics-of-planet-earth/Centre-for-the-Mathematics-of-Planet-Earth.aspx was one of 6 winners of the Whitehead Prize announced on 29th June 2018 by the London Mathematical Society (LMS), and was awarded with this prize for his work in statistical physics to the theory and modelling of climate dynamics, along with his pioneering leadership in mathematics applied to climate science.
- Published on 11 July 2018
A new study reveals how to best evaluate the circulation of magnetic fields around closed loops
Concerns about the effects of magnetic fields on human health require careful monitoring of our exposure to them. Mandatory exposure limits have been defined for electric and hybrid vehicle architectures, in domestic and work environments, or simply to shelter sensitive devices from unintended sources of magnetic disturbance. In a new study published in EPJ Plus, physicists Jose Manuel Ferreira and Joaquim Anacleto from the Trás-os-Montes e Alto Douro University in Portugal develop a method for deriving an approximate value of the circulation around a loop of the magnetic field generated by the flow of electric current in an arbitrarily-shaped wire of a given length.
- Published on 11 July 2018
Insights into its 100-year history reveal how the cosmological constant was marginalised by physicists before being reinstated by astronomers to explain the accelerated expansion of the universe
Physicists are now celebrating the 100th anniversary of the cosmological constant. On this occasion, two papers recently published in EPJ H highlight its role in modern physics and cosmology. Although the term was first introduced when the universe was thought to be static, today the cosmological constant has become the main candidate for representing the physical essence believed to be responsible for the accelerated expansion of our universe. Before becoming widely accepted, the cosmological constant was during decades the subject of many discussions about its necessity, its value and its physical essence. Today, there are still unresolved problems in understanding the deep physical nature of the phenomena associated with the cosmological constant.>
- Published on 11 July 2018
Quantum secret-sharing scheme for noisy environments
To protect the confidentiality of a message during its transmission, people encrypt it. However, noise in the transmission channels can be a source of concern regarding how faithful the message transmission may be after it has been decrypted. This is particularly important for secrets shared using quantum scale messengers. For example, a classical secret takes the shape of a string of zeros and ones, whereas a quantum secret is akin to an unknown quantum state of two entangled particles carrying the secret. This is because no two quantum particles can be in the same state at any given time. In a new study published in EPJ D, Chen-Ming Bai from Shaanxi Normal University, Xi’an, China, and colleagues calculate the degree of fidelity of the quantum secret once transmitted and explore how to avoid eavesdropping.
- Published on 10 July 2018
The publishers of The European Physical Journal C – Particles and Fields are pleased to announce the appointment of Professor Kostas Skenderis as new Editor-in-Chief for Theoretical Physics II: Gravitation, Astroparticle Physics and Cosmology, General Aspects of Quantum Field Theories, and Alternatives, replacing Professor Ignatios Antoniadis.
Kostas Skenderis is Director of the Southampton Theory Astrophysics and Gravity (STAG) Research Centre and a Professor in Mathematical Sciences at the University of Southampton. His research interests are in high energy theoretical physics and string theory, and in particular in the study of holographic dualities, their foundations and their applications.
- Published on 04 July 2018
A new study investigates the extremely rapid changes in the density of electrons in specific sites of the caffeine molecules thanks to an ultra-fast laser pulse that persists long enough to be observed
Caffeine keeps physicists up at night. Particularly those concerned with the capacity of electrons to absorb energy. In a new study published in EPJ B, a Franco-Japanese team of physicists have used the caffeine molecule as a playground to test the effect of ionising radiation on its electrons as they approach excited states. Their model accounts for the ionisation phenomenon in electrons, which are in a site-specific, localised orbit in the caffeine molecule. The electron excitation leaves the door open to positive charge progression along a molecular backbone. Thomas Niehaus from Claude Bernard Lyon 1 University, France, and colleagues have now developed a method for quantifying this positive charge migration in line with the ultra-short laser impulse. The observed charge motion happens on an attosecond time scale charge rearrangements driven by nuclear motion.