Tag Archives: Pennsylvania State University

Gold’s origin in the universe due to cosmic collision

An hypothesis for gold’s origins was first mentioned here in a May 26, 2016 posting,

The link between this research and my side project on gold nanoparticles is a bit tenuous but this work on the origins for gold and other precious metals being found in the stars is so fascinating and I’m determined to find a connection.

An artist's impression of two neutron stars colliding. (Credit: Dana Berry / Skyworks Digital, Inc.) Courtesy: Kavli Foundation

An artist’s impression of two neutron stars colliding. (Credit: Dana Berry / Skyworks Digital, Inc.) Courtesy: Kavli Foundation

From a May 19, 2016 news item on phys.org,

The origin of many of the most precious elements on the periodic table, such as gold, silver and platinum, has perplexed scientists for more than six decades. Now a recent study has an answer, evocatively conveyed in the faint starlight from a distant dwarf galaxy.

In a roundtable discussion, published today [May 19, 2016?], The Kavli Foundation spoke to two of the researchers behind the discovery about why the source of these heavy elements, collectively called “r-process” elements, has been so hard to crack.

From the Spring 2016 Kavli Foundation webpage hosting the  “Galactic ‘Gold Mine’ Explains the Origin of Nature’s Heaviest Elements” Roundtable ,

Astronomers studying a galaxy called Reticulum II have just discovered that its stars contain whopping amounts of these metals—collectively known as “r-process” elements (See “What is the R-Process?”). Of the 10 dwarf galaxies that have been similarly studied so far, only Reticulum II bears such strong chemical signatures. The finding suggests some unusual event took place billions of years ago that created ample amounts of heavy elements and then strew them throughout the galaxy’s reservoir of gas and dust. This r-process-enriched material then went on to form Reticulum II’s standout stars.

Based on the new study, from a team of researchers at the Kavli Institute at the Massachusetts Institute of Technology, the unusual event in Reticulum II was likely the collision of two, ultra-dense objects called neutron stars. Scientists have hypothesized for decades that these collisions could serve as a primary source for r-process elements, yet the idea had lacked solid observational evidence. Now armed with this information, scientists can further hope to retrace the histories of galaxies based on the contents of their stars, in effect conducting “stellar archeology.”

Researchers have confirmed the hypothesis according to an Oct. 16, 2017 news item on phys.org,

Gold’s origin in the Universe has finally been confirmed, after a gravitational wave source was seen and heard for the first time ever by an international collaboration of researchers, with astronomers at the University of Warwick playing a leading role.

Members of Warwick’s Astronomy and Astrophysics Group, Professor Andrew Levan, Dr Joe Lyman, Dr Sam Oates and Dr Danny Steeghs, led observations which captured the light of two colliding neutron stars, shortly after being detected through gravitational waves – perhaps the most eagerly anticipated phenomenon in modern astronomy.

Marina Koren’s Oct. 16, 2017 article for The Atlantic presents a richly evocative view (Note: Links have been removed),

Some 130 million years ago, in another galaxy, two neutron stars spiraled closer and closer together until they smashed into each other in spectacular fashion. The violent collision produced gravitational waves, cosmic ripples powerful enough to stretch and squeeze the fabric of the universe. There was a brief flash of light a million trillion times as bright as the sun, and then a hot cloud of radioactive debris. The afterglow hung for several days, shifting from bright blue to dull red as the ejected material cooled in the emptiness of space.

Astronomers detected the aftermath of the merger on Earth on August 17. For the first time, they could see the source of universe-warping forces Albert Einstein predicted a century ago. Unlike with black-hole collisions, they had visible proof, and it looked like a bright jewel in the night sky.

But the merger of two neutron stars is more than fireworks. It’s a factory.

Using infrared telescopes, astronomers studied the spectra—the chemical composition of cosmic objects—of the collision and found that the plume ejected by the merger contained a host of newly formed heavy chemical elements, including gold, silver, platinum, and others. Scientists estimate the amount of cosmic bling totals about 10,000 Earth-masses of heavy elements.

I’m not sure exactly what this image signifies but it did accompany Koren’s article so presumably it’s a representation of colliding neutron stars,

NSF / LIGO / Sonoma State University /A. Simonnet. Downloaded from: https://www.theatlantic.com/science/archive/2017/10/the-making-of-cosmic-bling/543030/

An Oct. 16, 2017 University of Warwick press release (also on EurekAlert), which originated the news item on phys.org, provides more detail,

Huge amounts of gold, platinum, uranium and other heavy elements were created in the collision of these compact stellar remnants, and were pumped out into the universe – unlocking the mystery of how gold on wedding rings and jewellery is originally formed.

The collision produced as much gold as the mass of the Earth. [emphasis mine]

This discovery has also confirmed conclusively that short gamma-ray bursts are directly caused by the merging of two neutron stars.

The neutron stars were very dense – as heavy as our Sun yet only 10 kilometres across – and they collided with each other 130 million years ago, when dinosaurs roamed the Earth, in a relatively old galaxy that was no longer forming many stars.

They drew towards each other over millions of light years, and revolved around each other increasingly quickly as they got closer – eventually spinning around each other five hundred times per second.

Their merging sent ripples through the fabric of space and time – and these ripples are the elusive gravitational waves spotted by the astronomers.

The gravitational waves were detected by the Advanced Laser Interferometer Gravitational-Wave Observatory (Adv-LIGO) on 17 August this year [2017], with a short duration gamma-ray burst detected by the Fermi satellite just two seconds later.

This led to a flurry of observations as night fell in Chile, with a first report of a new source from the Swope 1m telescope.

Longstanding collaborators Professor Levan and Professor Nial Tanvir (from the University of Leicester) used the facilities of the European Southern Observatory to pinpoint the source in infrared light.

Professor Levan’s team was the first one to get observations of this new source with the Hubble Space Telescope. It comes from a galaxy called NGC 4993, 130 million light years away.

Andrew Levan, Professor in the Astronomy & Astrophysics group at the University of Warwick, commented: “Once we saw the data, we realised we had caught a new kind of astrophysical object. This ushers in the era of multi-messenger astronomy, it is like being able to see and hear for the first time.”

Dr Joe Lyman, who was observing at the European Southern Observatory at the time was the first to alert the community that the source was unlike any seen before.

He commented: “The exquisite observations obtained in a few days showed we were observing a kilonova, an object whose light is powered by extreme nuclear reactions. This tells us that the heavy elements, like the gold or platinum in jewellery are the cinders, forged in the billion degree remnants of a merging neutron star.”

Dr Samantha Oates added: “This discovery has answered three questions that astronomers have been puzzling for decades: what happens when neutron stars merge? What causes the short duration gamma-ray bursts? Where are the heavy elements, like gold, made? In the space of about a week all three of these mysteries were solved.”

Dr Danny Steeghs said: “This is a new chapter in astrophysics. We hope that in the next few years we will detect many more events like this. Indeed, in Warwick we have just finished building a telescope designed to do just this job, and we expect it to pinpoint these sources in this new era of multi-messenger astronomy”.

Congratulations to all of the researchers involved in this work!

Many, many research teams were  involved. Here’s a sampling of their news releases which focus on their areas of research,

University of the Witwatersrand (South Africa)

https://www.eurekalert.org/pub_releases/2017-10/uotw-wti101717.php

Weizmann Institute of Science (Israel)

https://www.eurekalert.org/pub_releases/2017-10/wios-cns101717.php

Carnegie Institution for Science (US)

https://www.eurekalert.org/pub_releases/2017-10/cifs-dns101217.php

Northwestern University (US)

https://www.eurekalert.org/pub_releases/2017-10/nu-adc101617.php

National Radio Astronomy Observatory (US)

https://www.eurekalert.org/pub_releases/2017-10/nrao-ru101317.php

Max-Planck-Gesellschaft (Germany)

https://www.eurekalert.org/pub_releases/2017-10/m-gwf101817.php

Penn State (Pennsylvania State University; US)

https://www.eurekalert.org/pub_releases/2017-10/ps-stl101617.php

University of California – Davis

https://www.eurekalert.org/pub_releases/2017-10/uoc–cns101717.php

The American Association for the Advancement of Science’s (AAAS) magazine, Science, has published seven papers on this research. Here’s an Oct. 16, 2017 AAAS news release with an overview of the papers,

https://www.eurekalert.org/pub_releases/2017-10/aaft-btf101617.php

I’m sure there are more news releases out there and that there will be many more papers published in many journals, so if this interests, I encourage you to keep looking.

Two final pieces I’d like to draw your attention to: one answers basic questions and another focuses on how artists knew what to draw when neutron stars collide.

Keith A Spencer’s Oct. 18, 2017 piece on salon.com answers a lot of basic questions for those of us who don’t have a background in astronomy. Here are a couple of examples,

What is a neutron star?

Okay, you know how atoms have protons, neutrons, and electrons in them? And you know how protons are positively charged, and electrons are negatively charged, and neutrons are neutral?

Yeah, I remember that from watching Bill Nye as a kid.

Totally. Anyway, have you ever wondered why the negatively-charged electrons and the positively-charged protons don’t just merge into each other and form a neutral neutron? I mean, they’re sitting there in the atom’s nucleus pretty close to each other. Like, if you had two magnets that close, they’d stick together immediately.

I guess now that you mention it, yeah, it is weird.

Well, it’s because there’s another force deep in the atom that’s preventing them from merging.

It’s really really strong.

The only way to overcome this force is to have a huge amount of matter in a really hot, dense space — basically shove them into each other until they give up and stick together and become a neutron. This happens in very large stars that have been around for a while — the core collapses, and in the aftermath, the electrons in the star are so close to the protons, and under so much pressure, that they suddenly merge. There’s a big explosion and the outer material of the star is sloughed off.

Okay, so you’re saying under a lot of pressure and in certain conditions, some stars collapse and become big balls of neutrons?

Pretty much, yeah.

So why do the neutrons just stick around in a huge ball? Aren’t they neutral? What’s keeping them together? 

Gravity, mostly. But also the strong nuclear force, that aforementioned weird strong force. This isn’t something you’d encounter on a macroscopic scale — the strong force only really works at the type of distances typified by particles in atomic nuclei. And it’s different, fundamentally, than the electromagnetic force, which is what makes magnets attract and repel and what makes your hair stick up when you rub a balloon on it.

So these neutrons in a big ball are bound by gravity, but also sticking together by virtue of the strong nuclear force. 

So basically, the new ball of neutrons is really small, at least, compared to how heavy it is. That’s because the neutrons are all clumped together as if this neutron star is one giant atomic nucleus — which it kinda is. It’s like a giant atom made only of neutrons. If our sun were a neutron star, it would be less than 20 miles wide. It would also not be something you would ever want to get near.

Got it. That means two giant balls of neutrons that weighed like, more than our sun and were only ten-ish miles wide, suddenly smashed into each other, and in the aftermath created a black hole, and we are just now detecting it on Earth?

Exactly. Pretty weird, no?

Spencer does a good job of gradually taking you through increasingly complex explanations.

For those with artistic interests, Neel V. Patel tries to answer a question about how artists knew what draw when neutron stars collided in his Oct. 18, 2017 piece for Slate.com,

All of these things make this discovery easy to marvel at and somewhat impossible to picture. Luckily, artists have taken up the task of imagining it for us, which you’ve likely seen if you’ve already stumbled on coverage of the discovery. Two bright, furious spheres of light and gas spiraling quickly into one another, resulting in a massive swell of lit-up matter along with light and gravitational waves rippling off speedily in all directions, towards parts unknown. These illustrations aren’t just alluring interpretations of a rare phenomenon; they are, to some extent, the translation of raw data and numbers into a tangible visual that gives scientists and nonscientists alike some way of grasping what just happened. But are these visualizations realistic? Is this what it actually looked like? No one has any idea. Which is what makes the scientific illustrators’ work all the more fascinating.

“My goal is to represent what the scientists found,” says Aurore Simmonet, a scientific illustrator based at Sonoma State University in Rohnert Park, California. Even though she said she doesn’t have a rigorous science background (she certainly didn’t know what a kilonova was before being tasked to illustrate one), she also doesn’t believe that type of experience is an absolute necessity. More critical, she says, is for the artist to have an interest in the subject matter and in learning new things, as well as a capacity to speak directly to scientists about their work.

Illustrators like Simmonet usually start off work on an illustration by asking the scientist what’s the biggest takeaway a viewer should grasp when looking at a visual. Unfortunately, this latest discovery yielded a multitude of papers emphasizing different conclusions and highlights. With so many scientific angles, there’s a stark challenge in trying to cram every important thing into a single drawing.

Clearly, however, the illustrations needed to center around the kilonova. Simmonet loves colors, so she began by discussing with the researchers what kind of color scheme would work best. The smash of two neutron stars lends itself well to deep, vibrant hues. Simmonet and Robin Dienel at the Carnegie Institution for Science elected to use a wide array of colors and drew bright cracking to show pressure forming at the merging. Others, like Luis Calcada at the European Southern Observatory, limited the color scheme in favor of emphasizing the bright moment of collision and the signal waves created by the kilonova.

Animators have even more freedom to show the event, since they have much more than a single frame to play with. The Conceptual Image Lab at NASA’s [US National Aeronautics and Space Administration] Goddard Space Flight Center created a short video about the new findings, and lead animator Brian Monroe says the video he and his colleagues designed shows off the evolution of the entire process: the rising action, climax, and resolution of the kilonova event.

The illustrators try to adhere to what the likely physics of the event entailed, soliciting feedback from the scientists to make sure they’re getting it right. The swirling of gas, the direction of ejected matter upon impact, the reflection of light, the proportions of the objects—all of these things are deliberately framed such that they make scientific sense. …

Do take a look at Patel’s piece, if for no other reason than to see all of the images he has embedded there. You may recognize Aurore Simmonet’s name from the credit line in the second image I have embedded here.

Cellulose- and chitin-based biomaterial to replace plastics?

Although the term is not actually used in the news release, one of the materials used to create a new biomaterial could safely be described as nanocellulose. From a Sept. 20, 2017 Pennsylvania State University (Penn State) news release (also on EurekAlert) by Jeff Mulhollem,

An inexpensive biomaterial that can be used to sustainably replace plastic barrier coatings in packaging and many other applications has been developed by Penn State researchers, who predict its adoption would greatly reduce pollution.

Completely compostable, the material — a polysaccharide polyelectrolyte complex — is comprised of nearly equal parts of treated cellulose pulp from wood or cotton, and chitosan, which is derived from chitin — the primary ingredient in the exoskeletons of arthropods and crustaceans. The main source of chitin is the mountains of leftover shells from lobsters, crabs and shrimp consumed by humans.

These environmentally friendly barrier coatings have numerous applications ranging from water-resistant paper, to coatings for ceiling tiles and wallboard, to food coatings to seal in freshness, according to lead researcher Jeffrey Catchmark, professor of agricultural and biological engineering, College of Agricultural Sciences.

“The material’s unexpected strong, insoluble adhesive properties are useful for packaging as well as other applications, such as better performing, fully natural wood-fiber composites for construction and even flooring,” he said. “And the technology has the potential to be incorporated into foods to reduce fat uptake during frying and maintain crispness. Since the coating is essentially fiber-based, it is a means of adding fiber to diets.”

The amazingly sturdy and durable bond between carboxymethyl cellulose and chitosan is the key, he explained. The two very inexpensive polysaccharides — already used in the food industry and in other industrial sectors — have different molecular charges and lock together in a complex that provides the foundation for impervious films, coatings, adhesives and more.

The potential reduction of pollution is immense if these barrier coatings replace millions of tons of petroleum-based plastic associated with food packaging used every year in the United States — and much more globally, Catchmark noted.

He pointed out that the global production of plastic is approaching 300 million tons per year. In a recent year, more than 29 million tons of plastic became municipal solid waste in the U.S. and almost half was plastic packaging. It is anticipated that 10 percent of all plastic produced globally will become ocean debris, representing a significant ecological and human health threat.

crab shells

The material is comprised of cellulose pulp from wood or cotton, and chitosan, derived from chitin, the primary ingredient in the exoskeletons of arthropods and crustaceans. The main source of chitin is shells from lobsters, crabs and shrimp. Image: © iStock Photo OKRAD

The polysaccharide polyelectrolyte complex coatings performed well in research, the findings of which were published recently in Green Chemistry. Paperboard coated with the biomaterial, comprised of nanostructured fibrous particles of carboxymethyl cellulose and chitosan, exhibited strong oil and water barrier properties. The coating also resisted toluene, heptane and salt solutions and exhibited improved wet and dry mechanical and water vapor barrier properties.

“These results show that polysaccharide polyelectrolyte complex-based materials may be competitive barrier alternatives to synthetic polymers for many commercial applications,” said Catchmark, who, in concert with Penn State, has applied for a patent on the coatings.

“In addition, this work demonstrates that new, unexpected properties emerge from multi-polysaccharide systems engaged in electrostatic complexation, enabling new high-performance applications.”

Catchmark began experimenting with biomaterials that might be used instead of plastics a decade or so ago out of concerns for sustainability. He became interested in cellulose, the main component in wood, because it is the largest volume sustainable, renewable material on earth. Catchmark studied its nanostructure — how it is assembled at the nanoscale.

He believed he could develop natural materials that are more robust and improve their properties, so that they could compete with synthetic materials that are not sustainable and generate pollution — such as the low-density polyethylene laminate applied to paper board, Styrofoam and solid plastic used in cups and bottles.

“The challenge is, to do that you’ve got to be able to do it in a way that is manufacturable, and it has to be less expensive than plastic,” Catchmark explained. “Because when you make a change to something that is greener or sustainable, you really have to pay for the switch. So it has to be less expensive in order for companies to actually gain something from it. This creates a problem for sustainable materials — an inertia that has to be overcome with a lower cost.”

lab vials

The amazingly sturdy and durable bond between carboxymethyl cellulose and chitosan is the key. The two very inexpensive polysaccharides, already used in the food industry and in other industrial sectors, have different molecular charges and lock together in a complex that provides the foundation for impervious films, coatings, adhesives and more. Image: Penn State

Funded by a Research Applications for Innovation grant from the College of Agricultural Sciences, Catchmark currently is working to develop commercialization partners in different industry sectors for a wide variety of products.

“We are trying to take the last step now and make a real impact on the world, and get industry people to stop using plastics and instead use these natural materials,” he said. “So they (consumers) have a choice — after the biomaterials are used, they can be recycled, buried in the ground or composted, and they will decompose. Or they can continue to use plastics that will end up in the oceans, where they will persist for thousands of years.”

Also involved in the research were Snehasish Basu, post-doctoral scholar, and Adam Plucinski, master’s degree student, now instructor of engineering at Penn State Altoona. Staff in Penn State’s Material Research Institute provided assistance with the project.

The U.S. Department of Agriculture supported this work. Southern Champion Tray, of Chattanooga, Tennessee, provided paperboard and information on its production for experiments.

Here’s a link to and a citation for the paper,

Sustainable barrier materials based on polysaccharide polyelectrolyte complexes by
Snehasish Basu, Adam Plucinski, and Jeffrey M. Catchmark. Green Chemistry 2017, 19, 4080-4092 DOI: 10.1039/C7GC00991G

This paper is behind a paywall. One comment, I found an anomaly on the page when I visited. At the top of the citation page, it states that this is issue 17 of Green Chemistry but the citation in the column on the right is “2017, 19 … “, which would be issue 19.

Getting too hot? Strap on your personal cooling unit

Individual cooling units for firefighters, foundry workers, and others working in hot conditions are still in the future but if Pennsylvania State University (Penn State) researchers have their way that future is a lot closer than it was. From an April 29, 2016 news item on Nanotechnology Now,

Firefighters entering burning buildings, athletes competing in the broiling sun and workers in foundries may eventually be able to carry their own, lightweight cooling units with them, thanks to a nanowire array that cools, according to Penn State materials researchers.

An April 28, 2016 Penn State news release by A’ndrea Elyse Messer, which originated the news item, describes some of the concepts and details some of the technology,

“Most electrocaloric ceramic materials contain lead,” said Qing Wang, professor of materials science and engineering. “We try not to use lead. Conventional cooling systems use coolants that can be environmentally problematic as well. Our nanowire array can cool without these problems.”

Electrocaloric materials are nanostructured materials that show a reversible temperature change under an applied electric field. Previously available electrocaloric materials were single crystals, bulk ceramics or ceramic thin films that could cool, but are limited because they are rigid, fragile and have poor processability. Ferroelectric polymers also can cool, but the electric field needed to induce cooling is above the safety limit for humans.

Wang and his team looked at creating a nanowire material that was flexible, easily manufactured and environmentally friendly and could cool with an electric field safe for human use. Such a material might one day be incorporated into firefighting gear, athletic uniforms or other wearables. …

Their vertically aligned ferroelectric barium strontium titanate nanowire array can cool about 5.5 degrees Fahrenheit using 36 volts, an electric field level safe for humans. A 500 gram battery pack about the size of an IPad could power the material for about two hours.

The researchers grow the material in two stages. First, titanium dioxide nanowires are grown on fluorine doped tin oxide coated glass. The researchers use a template so all the nanowires grow perpendicular to the glass’ surface and to the same height. Then the researchers infuse barium and strontium ions into the titanium dioxide nanowires.

The researchers apply a nanosheet of silver to the array to serve as an electrode.

They can move this nanowire forest from the glass substrate to any substrate they want — including clothing fabric — using a sticky tape.

“This low voltage is good enough for modest exercise and the material is flexible,” said Wang. “Now we need to design a system that can cool a person and remove the heat generated in cooling from the immediate area.”

This solid state personal cooling system may one day become the norm because it does not require regeneration of coolants with ozone depletion and global warming potentials and could be lightweight and flexible.

Here’s a link to and a citation for the paper,

Toward Wearable Cooling Devices: Highly Flexible Electrocaloric Ba0.67Sr0.33TiO3 Nanowire Arrays by Guangzu Zhang, Xiaoshan Zhang, Houbing Huang, Jianjun Wang, Qi Li, Long-Qing Chen, and Qing Wang. Advanced Materials DOI: 10.1002/adma.201506118 Article first published online: 27 APR 2016

© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

One final comment, I’m trying to imagine a sport where an athlete would willingly wear any material that adds weight. Isn’t an athlete’s objective is to have lightweight clothing and footwear so nothing impedes performance?

Acoustofluidics and lab-on-a-chip for asthma and tuberculosis diagnostics

This is my first exposure to acoustofluidics (although it’s been around for a few years) and it concerns lab-on-a-chip diagnostics for asthma and tuberculosis. From an Aug. 3, 2015 news item on Azonano,

A device to mix liquids utilizing ultrasonics is the first and most difficult component in a miniaturized system for low-cost analysis of sputum from patients with pulmonary diseases such as tuberculosis and asthma.

The device, developed by engineers at Penn State in collaboration with researchers at the National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health, and the Washington University School of Medicine, will benefit patients in the U.S., where 12 percent of the population, or around 19 million people, have asthma, and in undeveloped regions where TB is still a widespread and often deadly contagion.

“To develop more accurate diagnosis and treatment approaches for patients with pulmonary diseases, we have to analyze sample cells directly from the lungs rather than by drawing blood,” said Tony Jun Huang, professor of engineering science and mechanics at Penn State and the inventor, with his group, of this and other acoustofluidic devices based on ultrasonic waves. “For instance, different drugs are used to treat different types of asthma patients. If you know what a person’s immunophenotype is, you can provide personalized medicine for their particular disease.

A July 29, 2015 Pennsylvania State University news release, which originated the news item, describes the disadvantages of the current sputum analyses techniques and explains how this new technique in an improvement,

There are several issues with the current standard method for sputum analysis. The first is that human specimens can be contagious, and sputum analysis requires handling of specimens in several discrete machines. With a lab on a chip device, all biospecimens are safely contained in a single disposable component.

Another issue is the sample size required for analysis in the current system, which is often larger than a person can easily produce. The acoustofluidic sputum liquefier created by Huang’s group requires 100 times less sample while still providing accuracy equivalent to the standard system.

A further issue is that current systems are difficult to use and require trained operators. With the lab on a chip system, a nurse can operate the device with a touch of a few buttons and get a read out, or the patient could even operate the device at home. In addition, the disposable portion of the device should cost less than a dollar to manufacture.

Po-Hsun Huang, a graduate student in the Huang group and the first author on the recent paper describing the device in the Royal Society of Chemistry journal Lab on a Chip, said “This will offer quick analysis of samples without having to send them out to a centralized lab. While I have been working on the liquefaction component of the device, my lab mates are working on the flow cytometry analysis component, which should be ready soon. This is the first on-chip sputum liquefier anyone has developed.”

Stewart J. Levine, a Senior Investigator and Chief of the Laboratory of Asthma and Lung Inflammation in the Division of Intramural Research at NHLBI, said “This on-chip sputum liquefier is a significant advance regarding our goal of developing a point-of-care diagnostic device that will determine the type of inflammation present in the lungs of asthmatics. This will allow health care providers to individualize asthma treatments for each patient and advance the goal of bringing precision medicine into clinical practice.”

Here’s a link to and a citation for the paper,

An acoustofluidic sputum liquefier by Po-Hsun Huang, Liqiang Ren, Nitesh Nama, Sixing Li, Peng Li, Xianglan Yao, Rosemarie A. Cuento, Cheng-Hsin Wei, Yuchao Chen, Yuliang Xie, Ahmad Ahsan Nawaz, Yael G. Alevy, Michael J. Holtzman, J. Philip McCoy, Stewart J. Levine, and  Tony Jun Huang. Lab Chip, 2015,15, 3125-3131 DOI: 10.1039/C5LC00539F

First published online 17 Jun 2015

This is an open access paper but you do need to register for a free (British) Royal Society of Chemistry publishing personal account.

US Dept. of Agriculture awards $3.8M for nanotechnology research grants

I wonder just how much funding the US Dept. of Agriculture (USDA) is devoting to nanotechnology this year (2015). I first came across an announcement of $23M in the body of a news item about Zinkicide (my April 7, 2015 posting),

Found in Florida orchards in 2005, a citrus canker, citrus greening, poses a serious threat to the US state’s fruit industry. An April 2, 2105 news item on phys.org describes a possible solution to the problem,

Since it was discovered in South Florida in 2005, the plague of citrus greening has spread to nearly every grove in the state, stoking fears among growers that the $10.7 billion-a-year industry may someday disappear.

Now the U.S. Department of Agriculture has awarded the University of Florida a $4.6 million grant aimed at testing a potential new weapon in the fight against citrus greening: Zinkicide, a bactericide invented by a nanoparticle researcher at the University of Central Florida.

An April 29, 2015 article by Diego Flammini for Farm.com describes the latest USDA nanotechnology funding announcement,

In an effort to increase America’s food security, nutrition, food safety and environmental protection, the United States Department of Agriculture’s (USDA) National Institute of Food and Agriculture (NIFA) announced $3.8 million in nanotechnology research grants.

Flammini lists three of the eight recipients,

University of Georgia
With $496,192, the research team will develop different sensors that are able to detect fungal pathogens in crops. The project will also develop a smartphone app for farmers to have so they can access their information whenever necessary.

Rutgers University
The school will use its $450,000 to conduct a nationwide survey about nanotechnology and gauge consumer beliefs about it and its relationship to health. Among the specifics it will touch on is the use of visuals to communicate nanotechnology.

University of Massachusetts
The researchers will concentrate their $444,200 on developing a platform to detect pathogens in food that is better than the current methods.

A full list of the recipients can be found in the April 27, 2015 USDA news release featuring the $3.8M in awards,

  • The University of Georgia, Athens, Ga., $496,192
  • University of Iowa, Iowa City, Iowa., $496,180
  • University of Kentucky Research Foundation, Lexington, Ky., $450,000
  • University of Massachusetts, Amherst, Mass., $444,200
  • North Dakota State University, Fargo, N.D., $149,714
  • Rutgers University, New Brunswick. N.J., $450,000
  • Pennsylvania State University, University Park, University Park, Pa., $447,788
  • West Virginia University, Morgantown, W. Va., $496,168
  • University of Wisconsin-Madison, Madison, Wis., $450,100

You can find more details about the awards in this leaflet featuring the USDA project descriptions for the eight recipients.

Wacky oxide. biological synchronicity, and human brainlike computing

Research out of Pennsylvania State University (Penn State, US) has uncovered another approach  to creating artificial brains (more about the other approaches later in this post), from a May 14, 2014 news item on Science Daily,

Current computing is based on binary logic — zeroes and ones — also called Boolean computing. A new type of computing architecture that stores information in the frequencies and phases of periodic signals could work more like the human brain to do computing using a fraction of the energy of today’s computers.

A May 14, 2014 Pennsylvania State University news release, which originated the news item, describes the research in more detail,

Vanadium dioxide (VO2) is called a “wacky oxide” because it transitions from a conducting metal to an insulating semiconductor and vice versa with the addition of a small amount of heat or electrical current. A device created by electrical engineers at Penn State uses a thin film of VO2 on a titanium dioxide substrate to create an oscillating switch. Using a standard electrical engineering trick, Nikhil Shukla, a Ph.D. student in the group of Professor Suman Datta and co-advised by Professor Roman Engel-Herbert at Penn State, added a series resistor to the oxide device to stabilize their oscillations over billions of cycles. When Shukla added a second similar oscillating system, he discovered that over time the two devices would begin to oscillate in unison. This coupled system could provide the basis for non-Boolean computing. The results are reported in the May 14 [2014] online issue of Nature Publishing Group’s Scientific Reports.

“It’s called a small-world network,” explained Shukla. “You see it in lots of biological systems, such as certain species of fireflies. The males will flash randomly, but then for some unknown reason the flashes synchronize over time.” The brain is also a small-world network of closely clustered nodes that evolved for more efficient information processing.

“Biological synchronization is everywhere,” added Datta, professor of electrical engineering at Penn State and formerly a Principal Engineer in the Advanced Transistor and Nanotechnology Group at Intel Corporation. “We wanted to use it for a different kind of computing called associative processing, which is an analog rather than digital way to compute.” An array of oscillators can store patterns, for instance, the color of someone’s hair, their height and skin texture. If a second area of oscillators has the same pattern, they will begin to synchronize, and the degree of match can be read out. “They are doing this sort of thing already digitally, but it consumes tons of energy and lots of transistors,” Datta said. Datta is collaborating with co-author and Professor of Computer Science and Engineering, Vijay Narayanan, in exploring the use of these coupled oscillations in solving visual recognition problems more efficiently than existing embedded vision processors as part of a National Science Foundation Expedition in Computing program.

Shukla and Datta called on the expertise of Cornell University materials scientist Darrell Schlom to make the VO2 thin film, which has extremely high quality similar to single crystal silicon. Georgia Tech computer engineer Arijit Raychowdhury and graduate student Abhinav Parihar mathematically simulated the nonlinear dynamics of coupled phase transitions in the VO2 devices. Parihar created a short video* simulation of the transitions, which occur at a rate close to a million times per second, to show the way the oscillations synchronize. Penn State professor of materials science and engineering Venkatraman Gopalan used the Advanced Photon Source at Argonne National laboratory to visually characterize the structural changes occurring in the oxide thin film in the midst of the oscillations.

Datta believes it will take seven to ten years to scale up from their current network of two-three coupled oscillators to the 100 million or so closely packed oscillators required to make a neuromorphic computer chip. One of the benefits of the novel device is that it will use only about one percent of the energy of digital computing, allowing for new ways to design computers. Much work remains to determine if VO2 can be integrated into current silicon wafer technology. “It’s a fundamental building block for a different computing paradigm that is analog rather than digital,” Shukla concluded.

There are two papers being published about this work,

Synchronizing a single-electron shuttle to an external drive by Michael J Moeckel, Darren R Southworth, Eva M Weig, and Florian Marquardt. New J. Phys. 16 043009 doi:10.1088/1367-2630/16/4/043009

Synchronized charge oscillations in correlated electron systems by Nikhil Shukla, Abhinav Parihar, Eugene Freeman, Hanjong Paik, Greg Stone, Vijaykrishnan Narayanan, Haidan Wen, Zhonghou Cai, Venkatraman Gopalan, Roman Engel-Herbert, Darrell G. Schlom, Arijit Raychowdhury & Suman Datta. Scientific Reports 4, Article number: 4964 doi:10.1038/srep04964 Published 14 May 2014

Both articles are open access.

Finally, the researchers have provided a video animation illustrating their vanadium dioxide switches in action,

As noted earlier, there are other approaches to creating an artificial brain, i.e., neuromorphic engineering. My April 7, 2014 posting is the most recent synopsis posted here; it includes excerpts from a Nanowerk Spotlight article overview along with a mention of the ‘brain jelly’ approach and a discussion of my somewhat extensive coverage of memristors and a mention of work on nanoionic devices. There is also a published roadmap to neuromorphic engineering featuring both analog and digital devices, mentioned in my April 18, 2014 posting.

Inhibiting pathogens in meat with edible antimicrobial films

Food poisoning is, at best, unpleasant and, at worst, lethal, so anything which helps people and other animals to avoid that condition is to be lauded, assuming there are no significant shortcomings with the solution to avoiding bad meat. According to a May 4, 2014 news item on Nanowerk a team at Penn (Pennsylvania) State University has developed an antimicrobial, edible film which may help solve the problem,

Antimicrobial agents incorporated into edible films applied to foods to seal in flavor, freshness and color can improve the microbiological safety of meats, according to researchers in Penn State’s College of Agricultural Sciences.

Using films made of pullulan — an edible, mostly tasteless, transparent polymer produced by the fungus Aureobasidium pulluns — researchers evaluated the effectiveness of films containing essential oils derived from rosemary, oregano and nanoparticles against foodborne pathogens associated with meat and poultry.

A May 1, 2014 Penn State University news release by Jeff Mulhollem, which originated the news item, describes the research in further detail,

In the study, which was published online in the April issue of the Journal of Food Science, researchers determined survivability of bacterial pathogens after treatment with 2 percent oregano essential oil, 2 percent rosemary essential oil, zinc oxide nanoparticles or silver nanoparticles.

The compounds then were incorporated into edible films made from pullulan, and the researchers determined the antimicrobial activity of these films against bacterial pathogens inoculated onto petri dishes.

Finally, the researchers experimentally inoculated fresh and ready-to-eat meat and poultry products with bacterial pathogens, treated them with the pullulan films containing the essential oils and nanoparticles, vacuum packaged, and then evaluated for bacterial growth following refrigerated storage for up to three weeks.

“The results from this study demonstrated that edible films made frompullulan and incorporated with essential oils or nanoparticles have the potential to improve the safety of refrigerated, fresh or further-processed meat and poultry products,” said Cutter. “The research shows that we can apply these food-grade films and have them do double duty — releasing antimicrobials and imparting characteristics to protect and improve food we eat.”

The edible films are a novelbut effective way to deliver antimicrobial agents to meats, Cutter explained, because the bacteria-killing action is longer lasting. Liquid applications run off the surface, are not absorbed and are less effective. The pullulan films adhere to the meat, allowing the incorporated antimicrobials to slowly dissolve, providing immediate and sustained kill of bacteria. In addition, the microorganisms do not have the opportunity to regrow.

There’s at least one problem with the pullulan films and its not, as far as the researcher is concerned, the silver or zinc oxide nanoparticles (from the news release),

Cutter conceded that pullulan films are not as oxygen-impermeable as plastic packaging now used to package meats, so the edible films are not likely to replace that material.

“The meat industry likes the properties of the polyethylene vacuum packaging materials that they are using now,” she said. “However, the one thing I really want to be able to do in the next few years is to figure out a way to co-extrude antimicrobial, edible films with the polyethylene so we have the true oxygen barrier properties of the plastic with the antimicrobial properties of the edible film.”

Knowing that edible films can release antimicrobials slowly over time and keep bacteria in meat at bay, further research will be aimed at creating what Cutter referred to as “active packaging” — polyethylene film with antimicrobial properties.

“Right now, we have two different packaging materials that are not necessarily compatible, leading to a two-step process. I keep thinking there’s a way to extrude edible, antimicrobial film in one layer with polyethylene, creating all-in-one packaging.

“The chemistry of binding the two together is the challenge, but we need to find a way to do it because marrying the two materials together in packaging would make foods — especially meat and poultry — safer to eat.”

Here’s a link to and a citation for the paper,

Incorporation of Essential Oils and Nanoparticles in Pullulan Films to Control Foodborne Pathogens on Meat and Poultry Products by Mohamed K. Morsy, Hassan H. Khalaf, Ashraf M. Sharoba, Hassan H. El-Tanahi and Catherine N. Cutter. Journal of Food Science, April 2014, Volume 79, Issue 4, pages M675–M684. DOI: 10.1111/1750-3841.12400 Article first published online: 12 MAR 2014

© 2014 Institute of Food Technologists®

This is behind a paywall.

US soldiers get batteries woven into their clothes

Last time I wrote about soldiers, equipment, and energy-efficiency (April 5, 2012 posting) the soldiers in question were British. Today’s posting focuses on US soldiers. From the May 7, 2012 news item on Nanowerk,

U.S. soldiers are increasingly weighed down by batteries to power weapons, detection devices and communications equipment. So the Army Research Laboratory has awarded a University of Utah-led consortium almost $15 million to use computer simulations to help design materials for lighter-weight, energy efficient devices and batteries.

“We want to help the Army make advances in fundamental research that will lead to better materials to help our soldiers in the field,” says computing Professor Martin Berzins, principal investigator among five University of Utah faculty members who will work on the project. “One of Utah’s main contributions will be the batteries.”

Of the five-year Army grant of $14,898,000, the University of Utah will retain $4.2 million for research plus additional administrative costs. The remainder will go to members of the consortium led by the University of Utah, including Boston University, Rensselaer Polytechnic Institute, Pennsylvania State University, Harvard University, Brown University, the University of California, Davis, and the Polytechnic University of Turin, Italy.

The new research effort is based on the idea that by using powerful computers to simulate the behavior of materials on multiple scales – from the atomic and molecular nanoscale to the large or “bulk” scale – new, lighter, more energy efficient power supplies and materials can be designed and developed. Improving existing materials also is a goal.

“We want to model everything from the nanoscale to the soldier scale,” Berzins says. “It’s virtual design, in some sense.”

“Today’s soldier enters the battle space with an amazing array of advanced electronic materials devices and systems,” the University of Utah said in its grant proposal. “The soldier of the future will rely even more heavily on electronic weaponry, detection devices, advanced communications systems and protection systems. Currently, a typical infantry soldier might carry up to 35 pounds of batteries in order to power these systems, and it is clear that the energy and power requirements for future soldiers will be much greater.” [emphasis mine]

“These requirements have a dramatic adverse effect on the survivability and lethality of the soldier by reducing mobility as well as the amount of weaponry, sensors, communication equipment and armor that the soldier can carry. Hence, the Army’s desire for greater lethality and survivability of its men and women in the field is fundamentally tied to the development of devices and systems with increased energy efficiency as well as dramatic improvement in the energy and power density of [battery] storage and delivery systems.”

Up to 35 lbs. of batteries? I’m trying to imagine what the rest of the equipment would weigh. In any event, they seem to be more interested in adding to the weaponry than reducing weight. At least, that’s how I understand “greater *lethality.” Nice of them to mention greater survivability too.

The British project is more modest, they are weaving e-textiles that harvest energy allowing British soldiers to carry fewer batteries. I believe field trials were scheduled for May 2012.

* Correction: leathility changed to lethality on July 31, 2013.

A brief reference to the Fukushima nuclear accident then, nanotechnology and cleaning up radioactive waste

I came across an excellent article about the Fukushima nuclear accident (courtesy @edyong209) that recounts the first 24 hours of  the emergency. It’s fascinating to find out what they did right and why it all went so wrong in 24 Hours at Fukushima by Eliza Strickland for the November 2011 issue of IEEE Spectrum (published by the Institute of Electrical and Electronics Engineers [IEEE]). Excerpted from the article,

True, the antinuclear forces will find plenty in the Fukushima saga to bolster their arguments. The interlocked and cascading chain of mishaps seems to be a textbook validation of the “normal accidents” hypothesis developed by Charles Perrow after Three Mile Island. Perrow, a Yale University sociologist, identified the nuclear power plant as the canonical tightly coupled system, in which the occasional catastrophic failure is inevitable.

On the other hand, close study of the disaster’s first 24 hours, before the cascade of failures carried reactor 1 beyond any hope of salvation, reveals clear inflection points where minor differences would have prevented events from spiraling out of control. Some of these are astonishingly simple: If the emergency generators had been installed on upper floors rather than in basements, for example, the disaster would have stopped before it began. And if workers had been able to vent gases in reactor 1 sooner, the rest of the plant’s destruction might well have been averted.

Strickland provides some historical context (Three Mile Island and Chernobyl nuclear accidents) in the addition to the 24 hour overview which provides details such as the fact that workers at the plant pulled the batteries out of their cars to generate some form of power after the plant generators failed.

Whether or not you believe we should be using nuclear, there can’t be any question that we have to deal with radioactive waste. From the Strickland article,

… So far, the cost of Fukushima is a dozen dead towns ringing the broken power station, more than 80 000 refugees, and a traumatized Japan.

On that note, the Nov. 2, 2011 news item (Nanotechnology makes storing radioactive waste safer) takes on some urgency. From the news item on Nanowerk,

Queensland University of Technology (QUT) researchers have developed new technology capable of removing radioactive material from contaminated water and aiding clean-up efforts following nuclear disasters.

The technology, which was developed in collaboration with the Australian Nuclear Science and Technology Organisation (ANSTO) and Pennsylvania State University in America, works by running the contaminated water through the fine nanotubes and fibres, which trap the radioactive Cesium (Cs+) ions through a structural change.

By adding silver oxide nanocrystals to the outer surface, the nanostructures are able to capture and immobilise radioactive iodine (I-) ions used in treatments for thyroid cancer, in probes and markers for medical diagnosis, as well as found in leaks of nuclear accidents.

“It is our view that just taking the radioactive material in the adsorbents isn’t good enough. We should make it safe before disposing it,” he [Professor Huai-Yong Zhu] said.

“The same goes for Australian sites where we mine nuclear products. We need a solution before we have a problem, rather than looking for fixes when it could be too late.”

“In France, 75 per cent of electricity is produced by nuclear power and in Belgium, which has a population of 10 million people there are six nuclear power stations,” he said.

“Even if we decide that nuclear energy is not the way we want to go, we will still need to clean-up what’s been produced so far and store it safely,” he said.

There’s no mention of commercializing this means of dealing with radioactive waste but I hope they manage it, or something better,  soon (from the news item),

“One gram of the nanofibres can effectively purify at least one tonne of polluted water,” Professor Zhu said.