JON CARTWRIGHT – Page 45 – & THREE QUARKS EDITORIAL

Making room for larger pores in zeolites

Chemistry WorldJon Cartwright15 July, 2011

Published in Chemistry World, 15 Jul 2011

Chemists in Korea and the US have come up with a method to create catalysts known as zeolites with a hierarchical range of pore sizes, making way for the reaction of larger molecules than ever before. According to the researchers, the new zeolites could be used in the petrochemical industry to crack oil, or in organic synthesis.

Zeolites – crystalline materials with dense internal networks of pores – are one of the most widely used catalysts in the chemical industry today. They are used for applications as diverse as water purification, trapping nuclear waste and cracking heavy oil into shorter hydrocarbons. However, the catalytic applications of zeolites to date have been limited to smaller molecules: zeolite pore mouths tend to be smaller than 0.8 nanometres, so molecules larger than this cannot enter. […]

The rest of this article is available here.

Physics student awaits espionage trial in Iran

Physics WorldJon Cartwright15 July, 2011

Published in Physics World, 15 Jul 2011

A doctoral student who was detained when he tried to leave his native Iran earlier this year will go on trial tomorrow for charges related to espionage, according to sources close to him.

Omid Kokabee has been detained since late January or February this year when he was attempting to fly from Tehran airport to return to his studies at the University of Texas at Austin, US. Physics Worldunderstands that he is suspected of leaking Iranian scientific information and working with the CIA.

The trial, apparently based on charges of illegal earnings and communicating with a hostile government, is expected to be headed by Iranian justice Abolghasem Salavati. […]

The rest of this article is available here.

Soft-drink cans beat the diffraction limit

NatureJon Cartwright8 July, 2011

Published in Nature, 8 Jul 2011

Sound, like light, can be tricky to manipulate on small scales. Try to focus it to a point much smaller than one wavelength and the waves bend uncontrollably — a phenomenon known as the diffraction limit. But now, a group of physicists in France has shown how to beat the acoustic diffraction limit — and all it needs is a bunch of soft-drink cans.

Scientists have attempted to overcome the acoustic diffraction limit before, but not using such everyday apparatus. The key to controlling and focusing sound is to look beyond normal waves to ‘evanescent’ waves, which exist very close to an object’s surface. Evanescent waves can reveal details smaller than a wavelength, but they are hard to capture because they peter out so quickly. To amplify them so that they become detectable, scientists have resorted to using advanced man-made ‘metamaterials’ that bend sound and light in exotic ways. […]

The rest of this article is available here.

Liquid cement turns liquid metal

Chemistry WorldJon Cartwright1 July, 2011

Published in Chemistry World, 1 Jul 2011

Concrete is heavy, tough and – you might think – a reliable insulator. But researchers in Japan have shown that, by doping it with free electrons, liquid cement can transform into a substance with metal-like electrical conductivity. According to the researchers, the surprising transition could lead to new types of semiconductor.

It has been known since the beginning of the nineteenth century that free electrons can be trapped in polar solvents such as water and ammonia. When an alkali metal is dissolved in ammonia, for example, the valence electrons are released into the solution, giving a deep blue colour when dilute and a bronze colour when more concentrated. These ‘solvated’ electrons are relatively stable, because each one is surrounded by an envelope of ammonia molecules. […]

The rest of this article is available here.

Rollerball writes electronics straight to paper

Chemistry WorldJon Cartwright27 June, 2011

Published in Chemistry World, 27 June 2011

Electronic circuits can be fiddly to make: engineers have to snap components onto a board or etch designs onto a copper surface. Now a US group of researchers has demonstrated that all you really need is a pen and some paper.

The new method, which uses a rollerball pen to be filled with conductive ink, could enable engineers to create one-off circuits that are cheap, flexible and disposable. ‘Pen-based printing allows one to construct electronic devices “on-the-fly”,’ says group leader Jennifer Lewis, at the University of Illinois at Urbana-Champaign. […]

The rest of this article is available here.

Self-Healing Sensor Can Take the Strain

ScienceJon Cartwright21 June, 2011

Published in ScienceNOW, 21 June 2011

Whether it’s monitoring the integrity of buildings during earthquakes or airplane wings during flight, so-called strain sensors are getting more and more important for our safety. But what if a sensor itself is broken? A pair of engineers claims to have developed an answer to this problem: a new type of strain sensor that heals itself as soon as it is damaged.

Strain is the amount that an object is stretched, bent, or deformed. Too much strain and a structure fractures, which is bad news if that structure happens to be keeping a building upright or people flying through the air. Some critical structures have sensors to continually record strain placed at various points, all linked up to a central hub, so that technicians can monitor it and flag areas for repair before any serious damage is done. […]

The rest of this article is available here.

Plasmon rulers measure in 3D

Chemistry WorldJon Cartwright16 June, 2011

Published in Chemistry World, 16 June 2011

Researchers in the US and Germany have used a plasmon ruler to show in principle how to measure the three dimensional position of objects at the nano-scale. The ruler, which consists of a stack of gold nano-rods, could one day be used to improve understanding of soft matter processes, such as protein folding.

Plasmon rulers consist of metal nanoparticles that are attached to biomolecules. Like tiny antennae, the nanoparticles create plasmon resonances – waves of electrons – that absorb or scatter light at specific visible or infrared frequencies. Because the exact frequency depends on the proximity of other particles, the nanoparticles offer a way to measure inter-particle distance. […]

The rest of this article is available here.

Magnets Keep Blood Flowing

ScienceJon Cartwright9 June, 2011

Published in ScienceNOW, 9 June 2011

Two physicists searching for a novel way to prevent heart attacks and strokes have discovered that strong magnetic fields can dramatically reduce the thickness, or viscosity, of blood flowing through a tube. The pair speculate that if this effect holds for blood in veins and arteries, scientists might someday develop a magnetic alternative to medicines designed to keep blood flowing in humans.

Strokes and heart attacks, the leading causes of death in the industrialized world, are often linked to high blood viscosity. Thicker blood damages blood vessels, and in repairing the damage, the vessels build up fatty deposits, which make strokes and heart attacks more likely. Currently, the only way to reduce blood viscosity is with drugs like aspirin, which inhibit the tendency of blood to clot. But aspirin has side effects: in high doses, it can lead to stomach bleeding, ulcers, and even tinnitus, or ringing of the ears. […]

The rest of this article is available here.

Brightest supernovae are in a class of their own

NatureJon Cartwright8 June, 2011

Published in Nature, 8 June 2011

Some of the brightest stellar explosions in the Universe should be classified together as a new type of supernova, according to an international collaboration of researchers. The group has catalogued six explosions that cannot easily be explained by any process yet known.

When stars several times more massive than our Sun die, they explode, forming supernovae. The process varies, but the result is a massive radiation of energy that can outshine an entire galaxy. Sometimes the radiation is produced by the radioactive decay of freshly generated elements, whereas in other cases it comes from an explosive release of heat or from a collision between debris ejected from the star and material surrounding it. […]

The rest of this article is available here.

Tohoku quake coincided with sky ‘anomalies’

Physics WorldJon Cartwright26 May, 2011

Published in Physics World, 26 May 2011

A preliminary analysis of the atmosphere and ionosphere over Japan in March reveals infrared and electron anomalies coincident with the Tohoku earthquake, researchers in the US and Russia claim. The anomalies are the latest evidence for a possible link between seismic activity and changes in the atmosphere or ionosphere, although sceptics believe they are unrelated.

Seismologists have searched for early-warning signals of earthquakes for more than a century. These range from small tremors in the ground, to aurora-like lights in the atmosphere and even to bizarre animal behaviour. But despite a few records of such incidents coming before quakes – usually noted retrospectively – there has never been any consistent method to accurately predict when a major shock is going to happen. […]

The rest of this article is available here.