Arsenic often appears in minerals rich in iron and sulphur, such as pyrite (fools’ gold). Scientists working as part of eMinerals, a major project funded under the Natural Environment Research Council’s e-Science programme, have found out precisely how arsenic is taken up and held in the pyrite structure and the factors likely to lead to its release. “We now know that arsenic replaces the sulphur in pyrite rather than the iron, and that pyrite is likely to dissolve more easily when arsenic is present,” says Dr Kate Wright, who worked on the project. Further work could identify ways of stabilising arsenic-containing iron sulphide rock by introducing additives that slow the rate at which it dissolves.
The eMinerals project found that a dioxin molecule will bind more strongly to clay surfaces the more chlorine atoms it contains, irrespective of the position of the chlorine atoms in the dioxin molecule. It also found that binding is stronger the greater the electrical charge on the surface. However, water competes with dioxin to bind to surfaces and, in practice, a dioxin molecule’s ability to bind to a surface is a balance between the binding strength of the dioxin to the surface, the water to the surface, and the dioxin to the water.
Both examples involved performing numerous simulations of the interactions between the different minerals in soil and rock with all the known variants of the contaminants. For example, there are 76 different variants of the dioxin molecule and numerous mineral surfaces in the environment to which they can attach, so hundreds of serious calculations are necessary.
The project has developed a grid infrastructure consisting of clusters and condor pools (including campus grids) at the collaborating institutions and resources held on the National Grid Service and the North West Grid. High performance computing resources can also be accessed for particularly large simulations if necessary.
Without access to such grid resources, researchers would have to perform all of the simulations sequentially, taking too much time to be practicable. Using the eMinerals infrastructure, they can submit all these jobs at once and see the results within a few hours. Results are automatically returned to a distributed data store with an interface that shows the files as if they are part of a single system. The data can be accessed remotely by collaborating scientists, as well as by those who originally submitted the job.
“We’re doing grid properly. We can submit hundreds of jobs from the user’s desktop to a number of different compute grids, and get the data back with metadata attached and with the analysis done - and in a state that enables collaborators to understand what the simulations are saying. We’re giving control back to the user,” says Professor Martin Dove, eMinerals principal investigator.
Scientists produce a new roadmap for guiding development & conservation in the Amazon
09.12.2016 | Wildlife Conservation Society
Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
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