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EPJ B Colloquium - Conjugated polymer-wrapped carbon nanotubes: physical properties and device applications

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s-SWNTs/PCBM heterojunction (Fig. 9c modified from Ref. [77] of the paper).

This EPJ B Colloquium presents an overview of the preparation method and physical properties of a new hybrid system consisting of single-walled carbon nanotubes (SWNTs) wrapped in conjugated polymers. The technique, which was first demonstrated in 2007, has attracted great interest owing to the high purity of the resulting semiconducting SWNTs and the possibility of applying them in electronic devices. Here, the authors review recent progress in the preparation of these nano-hybrids, their photophysical properties, and their applications in field-effect transistors and photovoltaic devices.

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EPJ D Colloquium - Modelling low energy electron and positron tracks in biologically relevant media

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An example of single electron tracks simulation in liquid water.

This EPJD colloquium describes an approach whereby the effect of low and intermediate energy (0-100 eV) electrons and positrons can be incorporated into radiation damage models, in particular the deceleration of these particles in biologically-relevant materials (water and representative biomolecules). At the heart of the modelling procedure is a C++ computer program called Low Energy Particle Track Simulation (LEPTS), which is compatible with commonly available general purpose Monte Carlo packages. Input parameters are carefully selected from theoretical and experimental cross-section data and energy loss distribution functions.

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EPJ E Highlight - Greater desertification control using sand trap simulations

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Spatial distribution of sand particles in the test straw checkerboard barrier.

A new simulation will help improve artificial sand-control measures designed to help combat desertification by identifying their weaknesses

In the fight against desertification, so-called straw checkerboard barriers (SCB), consisting of half -exposed criss-crossing rows of straw of wheat, rice, reeds, and other plants, play a significant role. The trouble is that our understanding of the laws governing wind-sand movement in SCB and their surrounding area is insufficient. Now, Ning Huang and colleagues from Lanzhou University in China, have performed a numerical simulation of the sand movement inside the SCB, described in a paper just published in EPJ E. Their country is particularly affected by desertification, which affects 18% of its territory. The results will help us to understand sand fixation mechanisms that are relevant for sandstorm and land-desertification control.

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EPJ B Highlight - Green photon beams more agile than optical tweezers

Charge-density computation of butane molecules.

A new manipulation tool exploits the fact that when light interacts with matter, it creates a force that produces material properties in macromolecules and biological cells

Romanian scientists have discovered a novel approach for the optical manipulation of macromolecules and biological cells. Their findings stem from challenging the idea that visible light would induce no physical effect on them since it is not absorbed. Instead, Sorin Comorosan, working as physicist at the National Institute for Physics and Nuclear Engineering based in Magurele, Romania, and as a biologist at the Fundeni Clinical Institute, Bucharest, Romania, and colleagues had the idea to use green photon beams. With them, it is possible to perform optical manipulation of macrostructures, such as biological proteins, with greater precision than with optical tweezers made from focused laser beams.

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EPJ A Highlight - Prompt x-rays emitted in neutron-induced fission help unveil the evolution of fission fragment charge yields as a function of incident neutron energy

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Charge distribution determined from the x-ray yield measurements (symbols) for different incident neutron intervals: threshold to 6MeV ~3MeV, from 6 to 11MeV ~8MeV, from 11 to 20MeV ~14MeV, from 20 to 50MeV ~32MeV and from 50to 400MeV ~180MeV. For more detail see text.

Nuclear fission is accompanied by the prompt emission of neutrons, gamma rays and x-rays. It has been known since the sixties that fission prompt x-rays originate essentially as a consequence of the internal conversions occurring in the prompt gamma deexcitation cascades of fission fragments.

This work presents for the first time a measurement of the prompt fission x-ray yields in 238U(n,f) for average incident neutron energies ranging from 3 to 200 MeV. These results provide new information on fission fragment deexcitation and allow testing the current knowledge of fission fragment nuclear structure. These results provide also a means to investigate the evolution, as a function of incident neutron energy, of fission fragment charge yields and elemental prompt x-ray emission probabilities.

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EPJ D Highlight - Pulsating dust cloud dynamics modelled

Different phases of a self-gravitational potential.

New research outlines a new design of spatio-temporal models of astrophysical plasmas

The birth of stars is an event that eludes intuitive understanding. It is the collapse of dense molecular clouds under their own weight that offers the best sites of star formation. Now, Pralay Kumar Karmakar from the Department of Physics at Tezpur University, Assam province, India, and his student have proposed a new model for investigating molecular clouds fluctuations at sites of star formation and thus study their pulsational dynamics, in a paper just published in EPJ D.

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EPJ B Highlight - Atom-based analogues to electronic devices

Spectral functions of the first (left panel) and the second (right panel) quantum dot.

New research gives a theoretical explanation as to how transport of single atoms is made possible through a chain of quantum dots

Scientists have pushed back the boundaries of atom-based transport, creating a current by charac-terising the many-body effects in the transport of the atoms along a periodic lattice. This work by Anton Ivanov and colleagues from the Institute for Theoretical Physics, at the University of Heidel-berg, Germany, adopted a new analytical approach before comparing it to approximate numerical simulations, and is reported in a paper recently published in EPJ B.

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EPJE news: Julia Yeomans awarded the EPJE P.-G. De Gennes lecture prize

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Julia Mary Yeomans.

The 2013 edition of the EPJE Pierre Gilles De Gennes prize has been awarded by the EPJE editors to Professor Julia Yeomans of the University of Oxford, UK. This initiative of the European Physical Journal E - Soft Matter and Biological Physics takes the name from the illustrious Nobel laureate who founded the journal.

Professor Yeomans has been nominated for her profound contribution to the study of the dynamical behaviour of complex and active liquids in confined geometries. She is an expert in theoretical and computational physics, particularly statistical physics, hydrodynamics, soft condensed matter and biological physics. Among her current research interests are microswimmers, active systems, liquid crystals and the interactions of fluids with structured surfaces.

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EPJ D Highlight - Novel beams made of twisted atoms

‘Snapshot’ of atomic Bessel beam profiles.

Scientists can now theoretically construct atomic beams of a particular kind, opening the door for applications in fields like quantum communication.

Physicists have, for the first time, now built a theoretical construct of beams made of twisted atoms. These findings are about to be published in EPJ D by Armen Hayrapetyan and colleagues at Ruprecht-Karls-University Heidelberg in Germany. These so-called atomic Bessel beams can, in principle, have potential applications in quantum communication as well as in atomic and nuclear processes.

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EPJ A Highlight - Dissecting Deuteron Compton Scattering I: The Observables with Polarised Initial States

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Sensitivity of a double-polarisation-asymmetry observable to the E1-M2 spin polarisability.

The electromagnetic polarisabilities of the nucleons characterise their responses to external fields. The simplest are the electric and magnetic polarisabilities that describe the induced dipole moments. For spin-1/2 particles there are also four spin polarisabilities, analogous to rotations of the polarisation of light by optically active media. The best experimental window on them is Compton scattering of photons, which has provided good determinations of the electric and magnetic polarisabilities of the proton. Future experiments with polarised protons will give access to its spin polarisabilities. In contrast, much less is known of about the neutron since it does not exist as a stable target. Nonetheless, its properties can be obtained from Compton scattering on light nuclei, most notably the deuteron -- a weakly bound proton and neutron. A new generation of experiments is planned to provide beams of polarised photons on targets of polarised deuterons. If the spins of the final particles are not observed, there are 18 independent observables. This work provides, for the first time, the complete set of these, which will be needed for the experimental analyses. More importantly, it also examines their sensitivities to the various polarisabilities, which will be crucial for the design of the experiments.

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Managing Editors
Anne Ruimy (EDP Sciences) and Sabine Lehr (Springer-Verlag)
Dear Sabine and Isabelle,
Thank you so much for all your help and excellent work you did on the EPJ ST volume "Nonlinear Dynamics of Deterministic and Stochastic Systems: Unraveling Complexity". This was a great experience and collaboration.

Alexander Neiman (on behalf of the guest editors), Ohio University, Athens, USA
Editor EPJ Special Topics 222/10, 2013

ISSN: 1951-6355 (Print Edition)
ISSN: 1951-6401 (Electronic Edition)

© EDP Sciences and Springer-Verlag