A new form of energy-transfer, reported today in Nature (3 July 2008) may have implications for the study of reactions going on in the atmosphere, and even for those occurring in the body.
Imagine a simple molecule consisting of two atoms as being like two balls attached together by a spring. If an incoming atom strikes one side of the molecule, the spring compresses and you would expect the molecule to jump backwards – remember Newton's cradle? (http://en.wikipedia.org/wiki/Newton's_cradle)
However, research by Dr Stuart Greaves in the Chemistry department at the University of Bristol, suggests that, contrary to expectations, in certain conditions the molecule jumps forwards, not backwards.
Greaves and his colleagues studied fast hydrogen atoms colliding with supersonically cooled deuterium-deuterium molecules. On the occasions when the collision did not result in a chemical reaction, the hydrogen atoms scatter.
In these 'inelastic' processes, the scattering of the hydrogen atom is normally backwards. But in this case, the team found that the inelastic scattering process led mainly to forward scattering – the opposite of what was expected.
Stuart Greaves said: "The reaction under study is the simplest chemical reaction possible and yet it still continues to surprise us, even after 80 years of scientific investigation. Our work provides another vital piece of the jigsaw for understanding the mechanics of chemical reactions, such as those going on in the atmosphere."
The explanation of what is happening is that even if the hydrogen atom flies past the deuterium-deuterium molecule in a 'grazing collision', this can tug on the deuterium atom nearest to it, thereby extending the bond connecting the two deuterium atoms, which causes the molecule to move forwards.
The authors suggest that this 'tug-of-war' behaviour may come into play whenever a strong attraction develops between the colliding partners, just as the gravitational effect of the Moon 'pulls' the water on Earth towards it.
Cherry Lewis | EurekAlert!
Biologists unravel another mystery of what makes DNA go 'loopy'
16.03.2018 | Emory Health Sciences
Scientists map the portal to the cell's nucleus
16.03.2018 | Rockefeller University
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...
The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...
At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.
When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...
At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.
Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...
16.03.2018 | Event News
13.03.2018 | Event News
08.03.2018 | Event News
16.03.2018 | Earth Sciences
16.03.2018 | Physics and Astronomy
16.03.2018 | Life Sciences