Scientists glimpse fresh aerosols from wildfire

Published in ERW, 11 Sep 2012

Researchers in Spain and France have glimpsed aerosols just a few hours after the start of a wildfire in southern Spain. The discovery, which allowed for a rare analysis of freshly produced aerosols from biomass burning, could help scientists understand the impact of wildfires on climate.

Aerosols are an important factor for climate as they can scatter sunlight back into space, thereby reducing global temperatures. A famous illustration of the effect came in 1991 with the eruption of Mount Pinatubo in the Philippines, when average global temperatures dropped by about 0.5 °C. […]

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Geoengineering is ‘comparatively inexpensive’

Published in Physics World, 31 Aug 2012

Researchers in the US have estimated that modification of stratospheric albedo – a widely discussed geoengineering technique to counteract some of the effects of climate change – could cost as little as $5bn a year. Although this is just a small fraction of the gross domestic product (GDP) of most western countries, the team stresses that there are many potential risks of geoengineering the planet in this way.

Geoengineering aims to mitigate man-made climate change by making large-scale modifications to the Earth’s surface or atmosphere. One of the main proposals discussed by scientists is stratospheric albedo modification: changing the reflective power of the atmosphere 10–50 km above the Earth’s surface so that more solar radiation is reflected back into space. Such a modification would be achieved by pumping tiny particles known as aerosols into the upper atmosphere. […]

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Geoengineering ‘comparatively inexpensive’

Published in ERW, 31 Aug 2012

Researchers in the US have estimated that modification of stratospheric albedo – a widely discussed geoengineering technique to counteract some of the effects of climate change – could cost as little as $5 bn a year. Although this is just a small fraction of the gross domestic product (GDP) of most western countries, the team stresses that there are many potential risks of geoengineering the planet in this way.

One of the main geoengineering proposals discussed by scientists is stratospheric albedo modification: changing the reflective power of the atmosphere 10–50 km above the Earth’s surface so that more solar radiation is reflected back into space. Sucha modification would be achieved by pumping tiny particles known as aerosols into the upper atmosphere. […]

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Can cold fusion research survive pioneer’s death?

Published in New Scientist, 22 Aug 2012

Martin Fleishmann kick-started cold fusion controversy and faced decades of hostility. His colleague Michael McKubre ponders the future of the field

Science advances one funeral at a time, said Max Planck. Now Martin Fleischmann is gone, what’s in store for cold fusion research?
I like that quote. It implies you’ve got to wait for the stubborn old bastards to die before you can make progress. But that wasn’t Planck’s intention: what he meant was that people refuse to even consider unorthodox arguments while their authors are still alive. Once they die, the argument becomes depersonalised. I do think there is an opportunity here. The hostility might abate because Martin is gone.

Fleischmann faced a backlash in 1989 when he and Stanley Pons said they had achieved fusion – the process that powers stars – in a lab. A bold claim that brought scorn for years.
They didn’t really claim that. They claimed to have observed an anomalous excess of heat in a tabletop experiment – a palladium electrode loaded with heavy hydrogen, or deuterium. That heat was too great to be explained by chemistry. When Martin and Stan first wrote their paper, they had a question mark after the word fusion. That question mark was removed, apparently, in the review and editing process. […]

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Why Deepwater Horizon led to snow

Published in ERW, 14 Aug 2012

Scientists in the US have put forward several mechanisms by which “marine snow” could have formed after the Deepwater Horizon oil spill. Their study, which offers a rare insight into the behaviour of marine snow in an oil environment, could help researchers understand how the oil was redistributed after the accident and how to tackle oil spills in the future.

Marine snow is the common name for the clumps of organic and inorganic matter – including bacteria, phytoplankton, faeces and bio-minerals – that form near the surface of the sea and fall steadily downwards. Most of the time marine-snow particles are millimetre- or centimetre-sized, although the snow has been found to be up to three metres in diameter in the Mediterranean. How such large particles are formed is a mystery but they are known to suffocate organisms on the sea floor. […]

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Too Much Rock ‘n’ Roll?

Published in Science, 10 Aug 2012

Anyone who attended the Bruce Springsteen concert at Ullevi Stadium in Gothenburg, Sweden, in 1985 will recall more than just good vibrations. During the star’s closing numbers, fans rocked the arena so hard that it needed millions of dollars’ worth of repairs. Now, engineers think they can estimate the impact of crowds in such situations—a method that could make stadiums, bridges, and other civil structures far more secure.

The forces of crowds on civil structures—known as crowd-induced loads—are a serious problem for designers. If loads get too high, a structure can visibly deform. Although the risk of collapse is usually small, people can panic and, in the worst cases, stampede. […]

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‘Genetic code’ guides nanoparticle growth

Published in Chemistry World, 9 Aug 2012

DNA – it is the basis for life, the blueprint from which proteins are created. Now, researchers in the US and China have demonstrated that DNA can also be used as a blueprint for the creation of non-biological structures. Their ‘genetic code’ could pave the way for tailored nanoparticles – fit for use as catalysts, or in surface-enhanced Raman spectroscopy (SERS).

Scientists have used DNA as a template to guide nanoparticle assembly before. It is DNA’s programmability – the numerous different combinations of nucleotides – that makes it so adaptable. If DNA is added to nanoparticles, it binds selectively, forming links that stick the nanoparticles together into interesting structures. […]

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Curiosity – searching in vain?

Published in Chemistry World, 2 Aug 2012

On 6 August, if all goes to plan, NASA’s Curiosity probe will touch down on a rocky crater close to the Martian equator. Its main mission objective is to look for signs of habitability – evidence that there is, or has been at some point in the past, conditions favourable to life. Yet amid the anxiety over the forthcoming landing, some scientists are wondering: if there are signs of habitability, will Curiosity be able to detect them?

The search for life on Mars has a long history, dating at least back to 1976, when NASA’s Viking landers explored the Red Planet. Those landers mixed into the Martian soil a radioactive nutrient solution and subsequently detected the emission of radioactive gas – a result that suggested the presence of microbial activity. Confusingly, however, another experiment on the landers found no evidence of organic compounds – and, by extension, no microbes. […]

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Upgrade old irrigation systems first, say scientists

Published in Environmental Research Web, 30 Jul 2012

Farmers are responding to the growing problem of water scarcity by upgrading their irrigation systems. But a study in Environmental Research Letters (ERL) shows that while new irrigation systems save water, the only sure way to also save energy is to prioritize the replacement of the oldest, most inefficient systems. Although the study focused on Australian agriculture, its authors say the results should apply elsewhere too.

According to United Nations estimates, by 2025 roughly 1.8 billion people will be living in regions of absolute water scarcity, while two-thirds of the world’s population will be living in water-stressed conditions. In Australia, the government considers the problem to lie in part with old irrigation systems. These include furrow irrigation, in which water is syphoned from nearby distribution channels, and hand-shift sprinklers, in which water is pumped through aluminium piping with sprinklers attached. […]

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Particle trapped with light and heat

Published in Physics World, 16 Jul 2012

Physicists in Germany have developed a trap for micron-sized particles that relies on both laser light and heat. The “optothermal” trap, which is built around a photonic crystal fibre, puts a new twist on microparticle trapping. The technique could offer a way to make precise measurements of the thermal forces acting on tiny particles and could even be used to sort and concentrate microparticles.

For more than 20 years it has been possible to trap microscopically small objects using light. The key development came in 1986 when Arthur Ashkin, Steven Chu and others at Bell Labs in the US invented what became known as optical tweezers: focused laser light that can hold microparticles in mid-space. The phenomenon works because dielectric particles are attracted to the region of strongest electric field, which is where the laser beam is focused. […]

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