Tag Archives: University of Adelaide

Australians protect grain with diatoms (Nature’s nanofabrication factories)

A Feb. 5, 2014 news item on Nanowerk highlights a presentation about protecting grain from insects given at the  ICONN2014-ACMM23 conference for nanoscience and microscopy held Feb. 3 -6, 2014 at the University of Adelaide (Australia). From the news item,

University of Adelaide researchers are using nanotechnology and the fossils of single-celled algae to develop a novel chemical-free and resistance-free way of protecting stored grain from insects.

The researchers are taking advantage of the unique properties of these single-celled algae, called diatoms. Diatoms have been called Nature’s nanofabrication factories because of their production of tiny (nanoscale) structures made from silica which have a range of properties of potential interest for nanotechnology.

“One area of our research is focussed on transforming this cheap diatom silica, readily available as a by-product of mining, into valuable nanomaterials for diverse applications – one of which is pest control,” says Professor Dusan Losic, ARC Future Fellow in the University’s School of Chemical Engineering.

The Feb. 5, 2014 University of Adelaide media release, which originated the news item, provides more insight into the research,

“There are two looming issues for the world-wide protection against insect pests of stored grain: firstly, the development of resistance by many species to conventional pest controls – insecticides and the fumigant phosphine – and, secondly, the increasing consumer demand for residue-free grain products and food,” Professor Losic says.

“In the case of Australia, we export grain worth about $8 billion each year – about 25 million tonnes – which could be under serious threat. We urgently need to find alternative methods for stored grain protection which are ecologically sound and resistance-free.”

The researchers are using a natural, non-toxic silica material based on the ‘diatomaceous earths’ formed by the fossilisation of diatoms. The material disrupts the insect’s protective cuticle, causing the insect to dehydrate.

“This is a natural and non-toxic material with a significant advantage being that, as only a physical mode of action is involved, the insects won’t develop resistance,” says Professor Losic. [emphasis mine]

“Equally important is that it is environmentally stable with high insecticidal activity for a long period of time. Therefore, stored products can be protected for longer periods of time without the need for frequent re-application.”

PhD student Sheena Chen is presenting her findings on the insecticidal activity of the material. PhD student John Hayles is also working on the project. The research is funded by the Grains Research and Development Corporation. The researchers are in the final stages of optimising the formula of the material.

This work be may of interest to Canadian farmers especially since 2013 featured the largest wheat and canola harvests in Canadian history according to a Dec. 4, 2013 article by Terryn Shiells for AgCanada.com,

“There’s just no getting around it, this is the biggest crop of Canadian history and it’s basically a shocker all around,” said Mike Jubinville of ProFarmer Canada in Winnipeg. “I really can’t think of a crop, other than peas and lentils, that didn’t provide an upside that betters what trade expectations were.”

Because all of the crops are so huge, it won’t be possible to move the entire crop this year, Jubinville said.

“We’re going to argue all we want about rail car allocations, about slow deliverable opportunities, but there’s just no way that the Canadian commercial handling system can move this crop,” he said.

Because there just isn’t enough capacity to get everything moved this year, there will also likely be larger than anticipated carryover stocks of all crops.

I imagine these bumper crops will mean there are storage issues which brings this piece back to the Australians and their work on preserving stored grain by using diatoms and silica material.  Perhaps Canadian farmers would like to test this “new natural and non-toxic material” once the formula has been optimized.

Australians inspired by Lycurgus Cup

The Lycurgus Cup is one of the great artistic achievements in history and there’s a nanotechnology twist to this art work created in the 4th century CE (or AD). From the Nov. 21, 2013 news item on Nanowerk,

A 1700-year-old Roman glass cup is inspiring University of Adelaide [Australia] researchers in their search for new ways to exploit nanoparticles and their interactions with light.

Researchers in the University’s Institute for Photonics and Advanced Sensing (IPAS) are investigating how to best embed nanoparticles in glass – instilling the glass with the properties of the nanoparticles it contains.

Before going further with this latest work at the University of Adelaide, here’s an excerpt from my Sept. 21, 2010 posting where I burbled on about the best of piece of writing I’ve seen about the Lycurgus Cup (held in the British Museum),

The *History of the Ancient World website (as Nov. 21, 2013 the link has been changed to the Université de Strasbourg,, Matière Condensée et Nanophysique website) recently featured a 2007 article about the Lycurgus Cup by Ian Freestone, Nigel Meeks, Margaret Sax and Catherine Higgitt for the Gold Bulletin, Vol. 40:4 (2007),

The Lycurgus Cup represents one of the outstanding achievements of the ancient glass industry. This late Roman cut glass vessel is extraordinary in several respects, firstly in the method of fabrication and the exceptional workmanship involved and secondly in terms of the unusual optical effects displayed by the glass.

The Lycurgus Cup is one of a class of Roman vessels known as cage cups or diatreta, where the decoration is in openwork which stands proud from the body of the vessel, to which it is linked by shanks or bridges Typically these openwork “cages” comprise a lattice of linked circles, but a small number have figurative designs, although none of these is as elaborate or as well preserved as the Lycurgus Cup. Cage cups are generally dated to the fourth century A.D. and have been found across the Roman Empire, but the number recovered is small, and probably only in the region of 50-100 examples are known. They are among the most technically sophisticated glass objects produced before the modern era.

Here’s what it looks like,

The Lycurgus Cup 1958,1202.1 in reflected light. Scene showing Lycurgus being enmeshed by Ambrosia, now transformed into a vine-shoot. Department of Prehistory and Europe, The British Museum. Height: 16.5 cm (with modern metal mounts), diameter: 13.2 cm. © The Trustees of the British Museum

The Lycurgus Cup 1958,1202.1 in reflected light. Scene showing Lycurgus being enmeshed by Ambrosia, now transformed into a vine-shoot. Department of Prehistory and Europe, The British Museum. Height: 16.5 cm (with modern metal mounts), diameter: 13.2 cm. © The Trustees of the British Museum

And this, too, is the one and only Lycurgus Cup,

The Lycurgus Cup 1958,1202.1 in transmitted light. Scene showing Lycurgus being enmeshed by Ambrosia, now transformed into a vine-shoot. Department of Prehistory and Europe, The British Museum. Height: 16.5 cm (with modern metal mounts), diameter: 13.2 cm. © The Trustees of the British Museum

The Lycurgus Cup 1958,1202.1 in transmitted light. Scene showing Lycurgus being enmeshed by Ambrosia, now transformed into a vine-shoot. Department of Prehistory and Europe, The British Museum. Height: 16.5 cm (with modern metal mounts), diameter: 13.2 cm. © The Trustees of the British Museum

The Nov. 21, 2013 University of Adelaide, news release, which originated the news item, explains why the Lycurgus Cup is of such interest, and why the same cup can be green or red

The Lycurgus Cup, a 4th century cup held by the British Museum in London, is made of glass which changes colour from red to green depending on whether light is shining through the Cup or reflected off it. It gets this property from gold and silver nanoparticles embedded in the glass.

“The Lycurgus Cup is a beautiful artefact which, by accident, makes use of the exciting properties of nanoparticles for decorative effect,” says Associate Professor Ebendorff-Heidepriem. “We want to use the same principles to be able to use nanoparticles for all sorts of exciting advanced technologies.”

Nanoparticles need to be held in some kind of solution. “Glass is a frozen liquid,” says Associate Professor Ebendorff-Heidepriem. “By embedding the nanoparticles in the glass, they are fixed in a matrix which we can exploit.”

Associate Professor Ebendorff-Heidepriem is leading a three-year Australian Research Council Discovery Project to investigate how best to embed nanoparticles; looking at the solubility of different types of nanoparticles in glass and how this changes with temperature and glass type, and how the nanoparticles are controlled and modified.

Practical applications, according to the news release, include,

“Nanoparticles and nanocrystals are the focus of research around the world because of their unique properties that have the potential to bring great advances in a wide range of medical, optical and electronic fields,” says Associate Professor Heike Ebendorff-Heidepriem, Senior Research Fellow in the University’s School of Chemistry and Physics. “A process for successfully incorporating nanoparticles into glass, will open the way for applications like ultra low-energy light sources, more efficient solar cells or advanced sensors that can see inside the living human brain.”

“We will be able to more readily harness these nanoscale properties in practical devices. This gives us a tangible material with nanoparticle properties that we can shape into useful forms for real-world applications. And the unique properties are actually enhanced by embedding in glass.”

Dragonflies: beautiful and smart according to Adelaide University (Australia) researchers

[downloaded from http://en.wikipedia.org/wiki/File:Tiffany_dragonfly_hg.jpg] Attribution: pendant Dragonfly - replica from the lamp by Louis Comfort Tiffany (50 cm diameter, 20 cm hight, about 400 glass pieces), Own work, Hannes Grobe 19:33, 20 June 2007 (UTC) Permission Own work, share alike, attribution required (Creative Commons CC-BY-SA-2.5)

[downloaded from http://en.wikipedia.org/wiki/File:Tiffany_dragonfly_hg.jpg] Attribution: pendant Dragonfly – replica from the lamp by Louis Comfort Tiffany (50 cm diameter, 20 cm hight, about 400 glass pieces), Own work, Hannes Grobe 19:33, 20 June 2007 (UTC) Permission Own work, share alike, attribution required (Creative Commons CC-BY-SA-2.5)

Long a subject of inspiration for artists, dragonflies have now been observed to exhibit signs of selective intelligence similar to human selective intelligence. From the Dec. 20, 2012 news release on EurekAlert,

In a discovery that may prove important for cognitive science, our understanding of nature and applications for robot vision, researchers at the University of Adelaide have found evidence that the dragonfly is capable of higher-level thought processes when hunting its prey.

The discovery, to be published online today in the journal Current Biology [link to article which behind a paywall], is the first evidence that an invertebrate animal has brain cells for selective attention, which has so far only been demonstrated in primates.

Here’s how the researchers made the observation (from the EurekAlert news release),

Using a tiny glass probe with a tip that is only 60 nanometers wide – 1500 times smaller than the width of a human hair – the researchers have discovered neuron activity in the dragonfly’s brain that enables this selective attention.

They found that when presented with more than one visual target, the dragonfly brain cell ‘locks on’ to one target and behaves as if the other targets don’t exist.

“Selective attention is fundamental to humans’ ability to select and respond to one sensory stimulus in the presence of distractions,” Dr Wiederman [Dr. Steven Wiederman, University of Adelaide] says.

Wiederman’s research partner suggests this observation has the potential for a number of widespread applications,

“Recent studies reveal similar mechanisms at work in the primate brain, but you might expect it there. We weren’t expecting to find something so sophisticated in lowly insects from a group that’s been around for 325 million years.

“We believe our work will appeal to neuroscientists and engineers alike. For example, it could be used as a model system for robotic vision. Because the insect brain is simple and accessible, future work may allow us to fully understand the underlying network of neurons and copy it into intelligent robots,” he [Associate Professor David O’Carroll, University of Adelaide] says.

You can find more information including pictures and a video in the Dec. 21, 2012 University of Adelaide news release.