News
EPJ B Highlight - Law governing anomalous heat conduction revealed
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- Published on 07 July 2015
Study finds the law governing how heat transport scales up with temperature
How heat travels, matters. Yet, there is still no consensus on the exact physical mechanism that causes anomalous heat conduction - despite the existence of previous numerical simulation, theoretical predictions and experimental observations. Now, a team based in Asia has demonstrated that electron transport depends on temperature. It follows a scaling governed by a power law - and not the exponential scaling previously envisaged. These findings were recently published in EPJ B by Yunyun Li Tongji University, Shanghai, China, and colleagues in Singapore.
EPJ Plus Highlight - Does that “green” plasticiser make my PVC flexible enough for you?
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- Published on 03 July 2015
A study of an eco-friendly solvent helping to make PVC plastic more flexible reveals the molecular-level interaction of hydrogen bonds between the two ingredients
What gives plastic objects their flexibility and reduces their brittleness is the concentration of plasticiser. For example, a chemical solvent of the phthalate family called DOP is often used. The trouble is there are concerns that phthalates present health risks. So there is a demand for more alternatives. Now, scientists from China have examined the effect of using DEHHP, a new eco-friendly plasticiser, used in combination with PVC. For a plasticiser to work, there has to be adequate hydrogen bonding with the plastic. By combining experiments and simulations, the team revealed why the polymer-solvent hydrogen bonding interaction's strength decreases with dilution at a molecular level—which is a phenomenon also observed in the DOP-PVC combination. These findings have been published in EPJ Plus by Yang Liu from Nanjing University and colleagues.
EPJ TI Review - Tip-enhanced Raman spectroscopy
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- Published on 03 July 2015
As part of the Thematic Series on Raman Spectroscopies, a new Review Article has just been published providing a detailed overview of the state-of-the-art in Tip-Enhanced Raman Spectroscopy (TERS). The authors discuss the capabilities of TERS, demonstrated through a summary of the major achievements of TERS techniques across many different fields of scientific research. It focuses on ongoing and potential applications of TERS including those in materials science, chemical science and biological science. Finally, the authors present an outlook on future development of the technique and the mechanisms being investigated to help achieve high signal enhancement and spatial resolution.
EPJ TI - Review of multidimensional data processing approaches for Raman and infrared spectroscopy
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- Published on 03 July 2015
A recent Review Article in EPJ Techniques and Instrumentation provides an overview of the latest data processing and pre-processing methods commonly used in Raman and IR spectroscopy, including imaging for better qualitative and quantitative analysis of biological samples.
Raman and Infrared (IR) spectroscopies provide information about the structure, functional groups and environment of the molecules in a sample. Over the past few decades Raman and IR microspectroscopy based techniques have been extensively used to understand fundamental biology and responses of living systems under diverse physiological and pathological conditions. The spectra from biological systems are complex and diverse, owing to their heterogeneous nature consisting of bio-molecules such as proteins, lipids, nucleic acids, carbohydrates etc. Therefore, interpretation of the results obtained is difficult and to overcome this various data mining methods are employed. These methods must be suitable for handling large multidimensional data sets and for exploring the complete spectral information simultaneously.
EPJ B Highlight - Structural shift elucidated with large-scale atomic simulations
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- Published on 30 June 2015
Iron-Nickel alloys’ structure changes as they heat up and cool down
Iron-nickel alloys are ubiquitous: they are found at the earth’s core and in meteorites. What is fascinating about such alloys is that their inner structure can change with rapid temperature swings. Heated up above 730 °C (1,340 °F), these alloys enter what is referred to as an austenitic phase. Alternatively, they can be turned into very hard alloys, referred to as a martensitic phase, by subjecting them to extremely rapid cooling. Now a team of scientists from Germany has, for the first time, created a large-scale simulation involving 275,000 atoms representing iron-nickel alloys in proportions found in nature. They show that transitions from one alloy structure to the other occurs in both an orderly and a disorderly way, depending on whether it is heated up or cooled down, respectively. These findings have been published in EPJ B by Emilia Sak-Saracino and Herbert Urbassek from the Research Center OPTIMAS at the University of Kaiserslautern, in Germany.
EPJ E Highlight - Improving insulation materials, down to wetting crossed fibres
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- Published on 30 June 2015
Scientists model the manner in which a liquid wets fibres, gaining useful insights for improving glass wool properties
Sandcastles are a prime example of how adding a small amount of liquid to a granular material changes its characteristics. But understanding the effect of a liquid wetting randomly oriented fibres in a fibrous medium remains a mystery. Relevant to the building industry, which uses glass wool, for instance, this phenomenon can be better understood by studying the behaviour of a liquid trapped between two parallel fibres. It can either remain in the shape of a drop or spread between the fibres into a long and thin column of liquid. Now, scientists have demonstrated that the spreading of the liquid is controlled by three key parameters: the amount of liquid on the fibres, the fibres’ orientation and the minimum distance between them. These findings, based on experimental and modelling work, were recently published in EPJ E. The authors are Alban Sauret, a scientist working at a laboratory jointly operated by the CNRS and Saint-Gobain, a building materials manufacturer in France, and international colleagues based at Princeton University and the NYU School of Engineering, USA.
EPJ E Colloquium - The role of acoustic streaming in vertically vibrated granular beds
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- Published on 30 June 2015
A recent EPJ E Colloquium by Jose Manuel Valverde looks at the fundamental physics that causes convection and fluidization in vibrated beds of particles with large inertia. The author examines the question of whether acoustic streaming arising from oscillatory viscous flows might play a role on the onset of convection and fluidization in vertically vibrated granular beds.
Acoustic streaming, first observed by Faraday in 1831, is an enigmatic phenomenon that has puzzled physicists for a long time. It occurs when a viscous fluid oscillates in the presence of a solid boundary. The dissipation of energy by viscous friction leads to a secondary steady circulation of fluid in a boundary layer near the surface of the solid, which enhances the gas-solid viscous interaction. Granular beds display, at sufficiently high vibrational intensities, surface patterns that bear a stunning resemblance to the surface ripples (Faraday waves) observed for low viscosity liquids. This suggests that the granular bed transits to a liquid-like regime, despite the large inertia of the particles.
EPJ D Highlight - Clues to inner atomic life from subtle light-emission shifts
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- Published on 29 June 2015
Hyperfine structure of light absorption by short-lived cadmium atom isotopes reveals characteristics of the nucleus that matter for high precision detection methods
Atoms absorb and emit light of various wavelengths. Physicists have long known that there are some tiny changes, or shifts, in the light that gets absorbed or emitted, due to the properties of the atomic nucleus. Now, a team of scientists has elucidated the so-called hyperfine structure of cadmium atoms. Relying on a method called laser spectroscopy, they have measured variations in the energy transition within cadmium atom - Cd in the periodic table. They studied a chain of isotopes with an odd number of neutrons ranging from 59 in 107Cd to 75 in 123Cd. From these high-precision measurements, they were able to identify the physical cause of the shift within the nucleus. These findings by Nadja Frömmgen from the Johannes Gutenberg University Mainz, in Germany, and international colleagues have now been published in EPJ D.
EPJB Colloquium: From seconds to months: the multi-scale dynamics of mobile telephone calls
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- Published on 24 June 2015
'Big Data' from electronic records derived from mobile telephone calls enables the study human behaviour and sociality in a quantitative way and with unprecedented statistical power. Cell phones are ubiquitous and Call Detail Records (CDRs), automatically collected by telecom operators are records of verified, time-stamped one-to-one communication. They are particularly useful to understand one-to-one communication patterns, as well as the dynamics of the social networks that are reflected in such patterns. In this EPJ B Colloquium, Jari Saramäki and Esteban Moro present an overview of empirical results pertaining to the multi-scale nature of social dynamics and networks, as inferred from CDRs.
EPJ issues findings from working group on peer review
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- Published on 24 June 2015
On 15 June 2015 EDP Sciences (Paris, France) have released information on the findings and recommendations of a working group into the peer review process. The meeting involved a committee of experts linked to the European Physical Journal (EPJ) including Editors-in-Chief, Associate-Editors, members of the Steering Committee and researchers involved in Scientific and Technical Information. EPJ itself, represents 25 European Physical Societies through its Scientific Advisory Committee.
