News
EPJ B Highlight - Trapping climate pollutant methane gas in porous carbon
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- Published on 01 December 2015
New adsorption of gas into porous carbon simulations are of interest to energy research and climate change mitigation
As talks of global warming are once again making headlines, scientists have renewed their efforts to understand how to best limit its effects. For example, sequestrating short-lived climate pollutants, such as methane and black carbon, yields much faster reductions in global warming compared to reductions in CO2. To do so, it is essential to have a better grasp of the nature of physico-chemical properties of gases interacting with porous carbon. Now, a team of chemical engineering researchers based in South Africa has established ways of accurately simulating methane adsorption and desorption in carbon with nanopores. These findings have been published by Matthew Lasich and Deresh Ramjugernath from the University of KwaZulu-Natal, Durban, South Africa, in EPJ B. Alternative applications for such findings are relevant for future energy research, such as energy storage and the development of natural gas extraction methods.
EPJ ST Highlight - Laser-based accelerators: yes, we CAN!
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- Published on 30 November 2015
Future ultra-fast high power lasers, dubbed Coherent Amplification Network (CAN) lasers, will deliver unprecedented accelerating power and efficiency
Few technologies have the power that particle accelerator technology has to touch upon such a broad range of applications at the many frontiers of modern science. Today, thanks to improvements in laser technology, a new generation of accelerators could soon emerge to replace accelerators relying on radio frequencies. In this new special issue, the journal EPJ Special Topics explores the requirements necessary to make such laser accelerators a reality, by presenting the work of the International Coherent Amplification Network (ICAN) research collaboration. Potential applications include future colliders, solutions for vacuum physics, design of Higgs-particle factories, creation of sources of high-flux protons and of neutrons, among others. Further, such accelerators open the door to solutions in nuclear pharmacology and proton therapy as well as orbital debris remediation.
EPJE Colloquium: Dense granular flows - fluidity revisited
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- Published on 28 November 2015
Bouzid et al.
In this new EPJ E Colloquium, a group of authors from ESPCI, Univ. Paris-Diderot and Univ. P.M. Curie use the interpretive frame-work of non-locality to describe the rheology and fluidity in dense granular flows. Is a “good fitting” of the velocity profiles sufficient to demonstrate the validity of a particular model for non-locality?
EPJ E Highlight - Liquid foam: plastic, elastic and fluid
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- Published on 27 November 2015
Snapshots of the foam at the exit of the convergent channel
What differentiates complex fluids from mere fluids? What makes them unique is that they are neither solid nor liquid. Among such complex fluids are foams. They are used as a model to understand the mechanisms underlying complex fluids flow. Now, a team of French physicists has gained new insights into predicting how complex fluids react under stretching conditions due to the interplay between elasticity, plasticity and flow. These findings were recently published in EPJ E by Benjamin Dollet and Claire Bocher from the Rennes Institute of Physics, in Brittany, France. Ultimately, potential applications include the design of new, optimised acoustic insulators based on liquid forms, or the mitigation of blast waves caused by explosions.
EPJ AP Highlight - Slowing dynamics of a supersonic beam
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- Published on 25 November 2015
The present investigation of the slowing dynamics of a supersonic atom beam by a counter-propagating resonant laser light, in other words the dynamics of atoms in a so-called “Zeeman slower”, is characterized by two special features which are: (i) a close coupling between simulations and experiments using a nozzle beam of metastable argon atoms, (ii) the use in the simulations of a Monte-Carlo (MC) scheme aimed at analysing step by step (i.e. subsequent cycles of absorption-emission) the slowing process and describing in a realistic way atom random walks due to the spontaneous emission. It allows us to get calculated 2D images and radial profiles of the slowed beam, in good agreement with experiment. Other important characteristics as angular aperture, velocity spreads, coherence radius (not easy to be measured experimentally), etc. also result from the simulation. Since the 3D atomic motion within the laser field is considered, border effects can be studied, while they were not directly accessible in a simple radiative force model. It is finally shown that the experimental characteristics of the slowed beam are reproduced by the calculated ones, assuming a point- like source. In general a laser beam is an efficient tool to manipulate the atomic motion and its interaction with atoms can be accurately characterized by means of the present MC-code. Actually any configuration combining resonant light and atoms is relevant (provided that the semi-classical approximation is valid), in particular the use of a “pushing” laser to generate a slow atomic beam from a magneto-optical trap is a technique which has been successfully tested with metastable argon atoms. Here again the MC-code has been able to accurately predict the characteristics of the generated beam.
EPJ D Highlight - Bringing the chaos in light sources under control
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- Published on 17 November 2015
Study investigates how best to stabilise the output of quantum dot LEDs
Noise is an issue in optical telecommunications. And findings means of controlling noise is key to physicists investigating light-emitting diodes or lasers. Now, an Italo-Iraqi team has worked on a particular type of light source, called the quantum dot light-emitting diode (QDLED). In a study published in EPJ D, Kais Al Namee from the National Institute of Optics, in Florence, Italy and colleagues, demonstrate that modulating bias current of the QDLED could lead to countering the noise. This, in turn, leads to stabilising such light sources, making them better suited for optical telecommunications.
EPJ Plus Focus Point - 3He replacement in neutron detection: Current status and perspectives
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- Published on 17 November 2015
One of the most important issues that the neutron community is currently facing is related to the lack of 3He for detection purposes. This problem has triggered an interesting and stimulating research and development activity worldwide, with the aim of finding effective and cheap solutions for 3He replacement. With the advent of new materials, advanced electronics and more powerful real time computing tools it has now become possible to investigate novel designs of neutron detectors to be used in various fields of research and technology, and to address the needs of more sophisticated applications.
The aim of this issue is to present an up-to-date, although not exhaustive, review on the R&D activities on 3He-free neutron detectors, with the aim of generating further discussions and activities on the subject, stimulate synergies between groups with different expertise, and show examples of existing neutron sources where new detectors and techniques can be tested and validated. This EPJ Plus Focus Point addresses all aspects related to the design of an innovative 3He-free neutron detector, from the development of new detection concepts and active material, to fast front-end electronics and acquisition systems, to the availability of neutron beams of suitable energy for detector characterization.
EPJ B Colloquium: Hierarchy of scales in language dynamics
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- Published on 12 November 2015
Language is a collective phenomenon, shared by a group of speakers, and originating from interactions between individual group members. This dimension has captured the interest of statistical physicists who have applied their methods to study how languages change and differentiate themselves from one another over time.
EPJ E Highlight - Zooplankton: not-so-passive motion in turbulence
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- Published on 10 November 2015
Physicists show that despite their limited swimming abilities, zooplankton called calanoid copepods display active, energetic behaviour in turbulent flows
Imagine a species that is only one millimetre long and has only a limited swimming ability. Yet, its mobility is sufficient for moving, feeding and reproducing in freshwater and seawater. That’s exactly what a type of zooplankton of the crustaceans family - namely the calanoid copepods - does. In a study published in EPJ E, physicists shed new light on how these zooplankton steer large-scale collective motion under strong turbulence. To do so, the authors study the zooplankton’s small-scale motion mechanisms when subjected to background flow motion. These findings are the work of François-Gaël Michalec from the Institute of Environmental Engineering, ETH Zurich, Switzerland, and European colleagues. Ecological applications in the field of zooplankton behaviour ecology include, for example, modelling the feeding efficiency of their predator, fish larvae.
EPJ H Highlight - May the 5th force be with you
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- Published on 27 October 2015
Ephraim Fischbach revisits the wealth of research emerging from the quest for the fifth force, which he hypothesised in the 1980s as being a new fundamental force in nature
Discovering possible new forces in nature is no mean task. The discovery of gravity linked to Newton’s arguably apocryphal apple experiment has remained anchored in popular culture. In January 1986, Ephraim Fischbach, Physics Professor from Purdue University in West Lafayette, Indiana, had his own chance to leave his mark on collective memory. His work made the front page of the New York Times after he and his co-authors published a study uncovering the tantalising possibility of the existence of a fifth force in the universe. In an article published in EPJ H, Fischbach gives a personal account of how the existence of the gravity-style fifth force has stimulated an unprecedented amount of research in gravitational physics - even though its existence, as initially formulated, has not been confirmed by experiment.
Subcategories
Topical Collections
Open calls for papers
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EPJ AM Call for papers: Themed Issue on Global Advances in Electromagnetic Metasurfaces for Space
(EPJ AM)
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Call for papers : Special Issue on Imaging, Diffraction, and Spectroscopy on the micro/nanoscale
(EPJ AP)