Tag Archives: technology

Nanotechnology and the Environment

Scientists working on the EC-funded research project Monacat,  are looking at how nanomaterials can remove water pollutants such as nitrates. “Nitrate reduction has been studied for decades; it’s very hard to do and it isn’t commercially viable,” says Alexei Lapkin, professor of chemical engineering at the University of Warwick, who works on Monocat.  Nitrates taken into the body through water can block oxygen transport. In severe cases this can starve tissues and organs of oxygen and lead to conditions including heart defects in babies. Nitrate levels are therefore strictly regulated, with an estimated €70bn–€320bn (£60bn –£274bn) spent every year across the EU removing nitrogen waste from water. The Monocat project has developed reactors coated with carbon nanotubes and nanofibres that could potentially remove nitrate pollutants at much lower costs. Lapkin says the most successful reactors will soon be chosen for patenting and further development.

Another European project, NanoGLOWA, is using nanotechnology to tackle global warming. The project aims to develop nanomembranes that can remove carbon dioxide from power plant emissions more efficiently than current methods. These membranes use nanomaterials to physically separate or chemically react with the carbon dioxide in flue gas streams.

As well as cleaning up fossil fuel use, nanotechnology is improving the viability of clean energy. Today, the most widespread photovoltaic solar cells are made of polycrystalline silicon and are relatively expensive, but nanotechnology is working to drive the costs of solar power down.  “It’s quicker and easier to grow a small crystal than a large one, and nanocrystals can be made in large quantities by simple chemical routes,” explains Jason Smith, leader of the Photonic Nanomaterials Group, University of Oxford. Photovoltaic cells made by “printing” nanoparticle inks are already commercially available.  “So far they have reached 17% efficiency,” says Smith. Normal polycrystalline silicon cells are about 20% efficient. “This is a pretty impressive achievement and demonstrates that nanomaterials can be almost as efficient as the standard polycrystalline silicon cells, while produced at a fraction of the cost.” An important next stage of the research will be to continue to improve the efficiency of these cheap nanoparticle cells…

“We will need at some point to replace internal combustion and diesel engines,” says Duncan Gregory, professor of inorganic materials at the University of Glasgow. “Hydrogen is an ideal fuel since one can extract a large amount of energy from it, and the process is green.”  However, storing hydrogen as a gas is both inconvenient and dangerous. “Solid-state storage, by which hydrogen is stored within a host solid, could overcome these problems, in principle making it possible to store a much higher amount of hydrogen in a relatively unreactive form,” Gregory says. He and his team have patented a nanomaterial called lithium nitride, similar in structure to carbon nanotubes and nanofibres, which may provide a way to store hydrogen safely inside a solid.

 

“It might be this material or similar that provides the breakthrough, or a completely different way of thinking,” says Gregory. “How soon this technology becomes ready depends on what the political will for change is. In these challenging economic times, real-terms government spending on research has fallen. Thankfully, energy remains a high UK research priority that will be essential, given all our environmental, economic and political concerns.”

New forms of glass that control the heat, light and glare passing through a surface are emerging. But these are based on nanotechnology procedures that, in some cases, have been around for decades.

Excerpt, Penny Sarchet, Essential matter, Guardian, Nov. 25, 2011

Subduing the masses–from heat rays to the dialogue police

The Roman emperors’ Praetorian Guard used cavalry and swords against stone-throwers. Their latter-day counterparts (human and equine) are better protected, with goggles, shields and other kit made of lightweight, flame-resistant, unshatterable and stab-proof materials.

They also have more ways of disrupting the rioters. Police in India spray unruly crowds with coloured water: stained and sodden agitators are easier to identify. America’s forces have developed (but not used) a “heat ray” designed to clear crowds by painfully zapping the skin. The unfamiliar tones of classical music can disperse loiterers, while big sound-blasters, known as “long-range acoustic devices” (LRADS), have been deployed against protesters in some American states. At a cost of up to $30,000 they can emit sound at 150-plus decibels (like a roaring jet engine at close range). Israel has a fancier version known as the “Scream” that affects the inner ear and induces nausea. When ochlophonics fail, authorities there have been known to douse Palestinian protesters with “skunk bombs” of smelly liquid.

Eyes are as vulnerable as ears and noses. A firm called Intelligent Optical Systems (Light Emitting Diode-Incapacitator, LEDI), based in California, is developing, with government backing, a strobe torch that makes targets dizzy and disoriented (at least within a range of 15 metres). Laser Energetics, in New Jersey, sells “Dazer Lasers” that emit a green beam capable of dazzling people up to 2.4km away.

Older methods may have political baggage. Water cannons are disliked in America because of their association with police brutality during the civil-rights era. The penchant for military-style responses is stronger in those continental European countries (and their colonies) where a paramilitary gendarmerie backs up a civic constabulary. The soldierly approach dates from Napoleonic times, when such forces browbeat conquered peasants into accepting the physical and symbolic power of the French state. Nowadays such forces are readier to fight protesters with distance weapons (such as rubber bullets) rather than grappling with them at close quarters, as British bobbies do.

Subtler methods can work too. Protests in Europe against Israel’s invasion of Gaza in 2009 quickly turned violent—but not in Sweden. A special unit in Stockholm, known as the Dialogue Police, is credited with this success. “They have legitimacy in the eyes of the community,” says Clifford Stott, an expert in crowd behaviour at the University of Liverpool, “because they facilitate peaceful protest, they don’t carry guns and they can’t arrest people.” Something for the ochlos and ochlophobes to ponder, as the cities smoulder.

New riot-control technology:The sound and the fury, Economist, Aug. 13, 2011, at 56