The finding emerged from some of the largest computer simulations ever attempted which required the pooled resources of supercomputers on three grids across two continents. The research is expected to provide insights into the properties of an important class of new materials, clay polymer nanocomposites, which are under investigation for many applications, for example as materials for use in car bodies.
Supercomputers on the UK National Grid Service, the US TeraGrid and DEISA (EU Distributed European Infrastructure for Supercomputing Applications), linked by dedicated high speed optical networks including UKLight, were pressed into service. Professor Peter Coveney and colleagues from University College London (UCL) used these resources to produce simulations of five computer models of the platelets that lock together to form clay sheets, the difference between each model being its size and complexity. Each model simulated accurately the motion and interactions between all the atoms in two sheets of clay separated by a layer of water and sodium ions. In the largest model, the motions of nearly 10 million atoms were taken into account. The simulations were run over timescales of up to 2 nanoseconds (a nanosecond is a billionth of a second).
By using distributed high performance computers linked by grids, it was possible to perform the many and vast simulations concurrently. Without such a facility, the time taken to perform the simulations on one supercomputer alone would have been too long to make the study practicable. The team was able to access these resources across multiple domains using grid middleware, called the Application Hosting Environment, which was originally developed under RealityGrid, an EPSRC funded e-Science project.
Data from the simulations were returned to computers back at UCL for visualisation. “Optical networks enabled us to link these grids together. The amount of data we produced is very large and UKLight is very valuable for getting the data back to us here,” says Professor Coveney.
The visualisations revealed the undulations. “As we moved from smaller to larger models we began to see collective undulations – the clay platelet sheets fluctuate up and down,” says Professor Coveney. This property, which was not known before in clay materials, is on too small a scale to be easily verified by experiment. But it has implications for the properties of clay on an ordinary scale which can be computed and then compared with experiment. For example, the team has used the response of the clay sheets to the undulations to calculate their elasticity (or Young’s modulus).
As a next step, the group plans to simulate clay platelets embedded in a polymer matrix. Such clay-polymer nanocomposites are under investigation for a number of applications ranging from car bodies and other automotive uses, through oilfield technology to drinks packaging. Compared with polymers alone, they have far greater mechanical strength, improved fire retardant properties and they make better barriers to the diffusion of gas. “These simulations will give us a better understanding of the properties of these new and important materials,” says Professor Coveney.
The work is published in the Journal of Physical Chemistry vol.111 pp8248-8259 2007.
Julia Short | alfa
New epidemic management system combats monkeypox outbreak in Nigeria
15.12.2017 | Helmholtz-Zentrum für Infektionsforschung
Gecko adhesion technology moves closer to industrial uses
13.12.2017 | Georgia Institute of Technology
DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.
Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...
MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.
Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
15.12.2017 | Power and Electrical Engineering
15.12.2017 | Materials Sciences
15.12.2017 | Life Sciences