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Sunday, January 31, 2010

Optical Coherence Tomography: New Early Detection Technique Will Help in Fight Against Cancer


NPL's Dr Pete Tomlins with a point spread phantom, a devices for the early detection of cancer.

 Image Credit: NPL 

The technique, Optical Coherence Tomography (OCT), is an increasingly popular method for looking beneath the surface of certain materials, notably human tissue. It is higher resolution and much quicker than techniques such as MRI or ultrasound, with no ionising radiation, making it ideal for detecting changes in tissue structure which can indicate the early stages of cancer.

However creating such images requires high precision, and any inaccuracy can lead to incorrect assumptions about cell disruption. This can mean missing opportunities for early, potentially life-saving treatment.

A new National Physical Laboratory ((NPL) Middlesex, UK) product, called a 'point-spread phantom', will eliminate the risk of such errors. The phantoms are translucent cylinders of resin containing specially arranged particles designed to reflect light in a very specific way. By viewing the phantom with an OCT machine and analysing the image with NPL software, users can be certain the machine is producing accurate images, which they can rely on for important medical decisions.

These 'phantoms' will also allow manufacturers of OCT technology to meet the necessary standards to guarantee to hospitals that their machines are sufficiently accurate. This will help speed the route to market of products using this important new technology, and assure hospitals of their ongoing reliability.

Michelson Diagnostics is the first UK company to use NPL's phantoms to validate the accuracy of their machines. CEO Jon Holmes said: "We developed breakthrough technology for imaging living tissue and for detecting diseases, but we needed to validate our performance claims, to provide customers with greater confidence in them. NPL's phantoms and analysis have enabled us to validate our claims beyond doubt, thereby demonstrating the superiority of our scanners and giving us the edge over our competitors. We expect that this validation will give OCT technology the backing it needs to become standard in hospitals around the world, and thereby make an important progression in the battle against cancer".

NPL recently completed laboratory tests and are now running trials with companies before bringing the product to market. Anyone interested in more information or trialing the new technology should contact Pete Tomlins

TU Delft Testing Thin Solar Tower to Power Building Extraction Ventilation


TU Delft (Delft, Netherlands) is going to test a 'solar chimney'. The tower, with a height of 11.5 meters, is heated up by the sun to produce an extraction ventilation effect applicable in buildings.
 
Image Credit:  TU Delft

Ventilation
This construction in the grounds of Peutz consultancy in Molenhoek, is slender, extremely well insulated and about 11.5m high. On the south-facing side (the sun side), the solar chimney is covered by a glass layer. This layer has good insulating properties but it also transmits solar radiation very well. The solar radiation hits an 'absorber plate' which in turn heats up the air in the chimney. The warm air rises, causing an updraught. Thus, a chimney like this can provide extraction ventilation in buildings.

Test cell
At the base of the chimney there is a small chamber (test cell) to house measuring and control apparatus and to condition the ventilation air. Air from this test cell is sucked up through the chimney. The test cell temperature is regulated with a heat pump so that it is suitable for offices and other buildings: 20ºC in winter and 24ºC in summer.

Taking measurements
The solar chimney is a test model for Ben Bronsema's PhD research at TU Delft. He is investigating the best way to build solar chimneys and the extent solar to which energy can contribute to heating systems in buildings. To achieve this, Bronsema is measuring pressure, temperature, air speed, solar radiation, wind speed etc. In this way, he hopes to help develop energy-efficient and innovative ways of ventilating and heating buildings.

This research is a joint project involving the architecture faculties at TU Delft and TU Eindhoven, and VVKH Architecten. It is being carried out with the aid of a grant from the Dutch Ministry of Economic Affairs; Energy Research Grant regulation, Long-Term (Article 18b).

For more information
Ben Bronsema, bronconsult@planet.nl
Science Information Officer TU Delft, r.e.t.meijer@tudelft.nl, +31 15 27 81751

Department of Homeland Security Seeks Bidders to Commercialize Magnetic Vision for Airport Screening, Device Would Permit Passengers to Take Fluid on Planes


Flyers may be able to board with liquids and gels if manufacturers can engineer smaller versions of this MagViz prototype.
Credit: DHS S&T and LANL

Remember 2005, when you could still board a plane with shampoo in your bag, toothpaste in your purse, a can of soda in your hand? Do those fluid memories hurt right down to your denture cream?

Washington feels your pain. As reported in 2008, researchers at the Energy Department's Los Alamos National Laboratory (LANL) have been fine-tuning magnetic resonance imaging (MRI) technology. By detecting ultralow magnetic fields, the lab's creation—the Magnetic Vision Innovative Prototype (or MagViz)—can peer through whatever container you're carrying, divine what's in it, and let you pass with your bottled water or—during flu season—your hand sanitizer.

The first MagViz was an overachiever. It was programmed to be extremely sensitive, but it came off a bit paranoid. It "saw" danger in certain off-brand shampoos and sport drinks. Since then, with funding and guidance from the Department of Homeland Security's Science and Technology Directorate (S&T), the LANL team has fine-tuned the technology.

Last year, to test the new model's selectivity, Department program evaluators planted a minefield of surprise liquids at Albuquerque International Airport. Their faith proved well-placed: Nothing nasty slipped past LANL's brainchild; MagViz correctly flagged all liquid-bomb ingredients.

At the same time, MagViz gave the green light to all but one friendly fluid. And it withstood everyday mishaps—an outsize bag; a refrigerator magnet from the airport gift shop; a stuck-open door; a false loading, wherein an edgy passenger snatched back her half-inserted purse. On the operator's display, threats were circled and lit up like Vegas, to the delight of screeners from the Transportation Security Administration (TSA).

Thanks to a user-friendly human interface, there's no mistaking where the threats are in this MagViz screen image.
Credit: DHS S&T and LANL

And yet, MagViz's precision does come with some challenges. In Albuquerque, the prototype had to be shielded from electromagnetic interference radiating from fluorescent ballasts, Wi-Fi laptops—even smartphones. That shielding came in the form of a hulking exoframe that would be too bulky for a real operational setting. To engineer a shielded MagViz in a compact enclosure, the Department will look to the private sector, where ingenuity often spells profit.

Envisioning far-reaching applications for the new invention, R&D Magazine recognized the LANL team with a coveted 2009 R&D 100 Award. Such laurels are welcome validators, says MagViz program manager Stephen Surko of S&T's Homeland Security Advanced Research Projects Agency (HSARPA). But if MagViz is to earn its place behind thousands of X-ray stations, it must catch dangerous liquids reliably, affordably, and swiftly, while flagging few types of liquors as evil spirits.

To this end, Surko is evaluating a variety of concepts of operation. In most, MagViz would be placed immediately behind the X-ray machine, giving each carry-on a second scan. In smaller airports, where the screening area may be too short for a tandem arrangement, MagViz would sit off to the side. "You'd have to wait in a separate line," concedes Surko, "but at least you could bring along that large bottle of H20."

MagViz would be a tremendous improvement, but don't expect miracles. Unlike a fingerprint, nuclear magnetic resonance signatures can vary. If, for example, a liquid is slightly warmer or cooler than expected, or its pH a bit more acidic or basic, the reading can change. "MagViz can see all these differences easily," says Surko. "We need to learn how well we can predict them and account for them."

The challenges—accounting for each such variance and shielding MagViz while keeping it trim—may prove a bridge too far. But if the departments of Homeland Security and Energy and the free market can cross each bridge, then traveling with toiletries, snow globes, and drinks may be a thing of the future, rather than the past.

On January 21, the Los Alamos National Laboratory (LANL) issued a public request (PDF, 4 pages - 41 KB) for ways to commercialize MagViz. If you think you have what this takes, please submit a letter of interest to LANL by February 12.

Canada Seeks to "Green" the Oil Patch with Fuel Cells and Carbon Emission Reductions


Two premier Government of Canada Research & Development organizations are partnering to reduce energy intensity and green house gasses (GHG) in oil production. This partnership was formalized through the signing of a memorandum of understanding (MOU) on January 26th between the National Research Council Institute for Fuel Cell Innovation (NRC-IFCI) and the Department of Natural Resources Canada's CanmetENERGY in Devon, Alberta.

CanmetENERGY conducts cutting-edge research and development on oil sands and heavy oil extraction, processing and upgrading, with an emphasis on environmental technologies. NRC-IFCI is a recognized world leader for research, development and testing of fuel cells and related clean energy technologies.

"By combining our complementary expertise in the traditional and clean energy sectors we can help green oil refining processes, significantly reducing energy consumption and greenhouse gas emissions" said NRC-IFCI Director General Maja Veljkovic. "This strategic partnership applies NRC's core fuel cell capabilities to the development, demonstration and commercialization of integrated clean energy solutions."

NRC-IFCI is already collaborating closely with CanmetENERGY with funding from NRCan's Program of Energy Research and Development (PERD) program to develop novel materials and catalysts that can improve the quality of heavy oil upgrading products, and to improve understanding of hydrocarbon chemical and thermophysical properties of the oil sand diesel fuels.

"This partnership will allow us to explore new more cost effective ways for CO2 capture through development of novel materials," said Hassan Hamza, Director General of CanmetENERGY.

NRCan's PERD Program directly supports energy research and development conducted in Canada by federal departments and agencies, and is concerned with all aspects of energy supply and use. NRC-IFCI and NRCan have collaborated previously on programs and projects related to fuel cells, components and applications. This collaboration also included the Hydrogen HighwayTM and the development of hydrogen fuelling station performance and verification guidelines.

About NRC and NRC-IFCI
Canada's National Research Council (NRC) is a leader in the development of an innovative, knowledge-based economy for Canada through science and technology, and was recently ranked among the Top 10 government organizations and NGOs for scientific output in fuel-cell research in the world. The NRC Institute for Fuel Cell Innovation (NRC-IFCI) supports Canadian leadership in fuel cell and clean energy technology by addressing industry-defined R&D and commercialization priorities.

About NRCan and CanmetENERGY in Devon, Alberta
Natural Resources Canada is dedicated to developing and deploying energy efficient, alternative energy and renewable energy technologies. CanmetENERGY in Devon focuses on research and development on oil sands and heavy oil extraction, processing and upgrading, with an emphasis on environmental technologies.

Fabrication Process for Large-Area Single- and Few-Layer Graphene on Arbitrary Substrates for Electronic Components Shown by MIT Team, Patterning by Lithographic Techniques


Massachusetts Institute of Technology (Cambridge, MA) Associate Professor of Electrical Engineering Jing Kong, Alfonso Reina Cecco and Mildred S. Dresselhaus created processes for the synthesis and fabrication of large-area graphene films on arbitrary substrates (i.e., any of a wide variety of substrates) and the fabrication of patterned graphene structures based on the synthesis method.

The resulting graphene film can be used in a variety of applications. For example, the graphene film can be used as a transparent electrode, as an ultrathin conducting electrode, as an electrode for a battery, as a transistor device (both for low and high frequency).  Graphene film may also be used as a sensor to detect a chemical or biological agent, as an optical detector, as an interconnect for an integrated circuit, as an on-chip capacitor for an integrated circuit, as an on-chip inductor for an integrated circuit, as a hetero-junction device (metal-semiconductor) including graphene nanoribbons with different crystal orientations.

 Further uses include as an in-plane thermal conductor to spread heat dissipation, as a quantum device or spintronic device, as a graphene-nanotube heterostructure (together with nanotubes), as a p-n junction diode or bi-polar junction transistor, as a device with an adjustable bandgap, and as an interface for different materials (e.g., for interfacing with Si, GaN and/or GaAs), according to U.S. Patent Application 20100021708.

A film of single-layer to few-layer graphene is formed by depositing a graphene film via chemical vapor deposition on a surface of a growth substrate. The surface on which the graphene is deposited can be a polycrystalline nickel film, which is deposited by evaporation on a SiO2/Si substrate. A protective support layer is then coated on the graphene film to provide support for the graphene film and to maintain its integrity when it is removed from the growth substrate. The surface of the growth substrate is then etched to release the graphene film and the protective support layer from the growth substrate, wherein the protective support layer maintains the integrity of the graphene film during and after its release from the growth substrate. After being released from the growth substrate, the graphene film and protective support layer can be applied onto an arbitrary target substrate for evaluation or use in any of a wide variety of applications.

In recent years, research on single- or few-layer graphene (SLG or FLG) has attracted much attention. "Graphene" refers to a single layer of hexagonal carbon structure. Single-layer-graphene and few-layer-graphene structures have been predicted and demonstrated to have many remarkable properties, such as high electron and hole mobilities with a symmetrical electron and hole band structure, high current-carrying capacity, high in-plane thermal conductivity, high tensile strength and high mechanical stability. When graphene is cut into narrow strips, it bears attributes very similar to those of carbon nanotubes, which have been investigated thoroughly.

However, there are many hurdles for the application of nanotubes due to the challenges of controlling the nanotube structures, whereas graphene strips or other structures can be patterned by conventional top-down lithography methods, which can be advantageous. The observation of an unconventional quantum Hall effect in graphene has also been reported and can be seen even at room temperature. The linear E(k) relationship in the electronic band structure of graphene gives rise to an unusual massless Dirac fermion behavior of the electrons. The electrical conductance of graphene is also sensitive to the absorption or desorption of even a single gas molecule. Graphene sheets, accordingly, show great potential as another materials option for electronic applications (e.g., for electronic devices, sensors or composite materials).

Though single- and few-layer graphene offer such significant advantages, the current methods for achieving single- and few-layer graphene are very limited. Existing methods include high-temperature vacuum annealing of SiC single-crystal substrates, hydrocarbon decomposition on single crystal metal substrates under ultra high vacuum (UHV) conditions, or manually cleaving highly oriented pyrolytic graphite (HOPG) using adhesive tape on SiO2 substrates. These methods are not well suited for large-scale manufacturing.   The MIT team has developed a process that lends itself to mass production.
 

After the transfer, the graphene film can be patterned via a lithography process, such as photolithography, electron-beam lithography and interference lithography. The metal film can be patterned by lithography before formation of the graphene film. Part of the metal surface can be protected with a covering to prevent graphene growth thereon so that a graphene pattern can be directly obtained. 

FIG. 1 illustrates the evaporation and deposition of a nickel film on a thermally grown oxide layer on a silicon (Si) substrate. FIG. 2 illustrates the subsequent production of a graphene film as the carbon-doped nickel film is cooled down.  FIG. 3 illustrates a full graphene coating on the nickel film.

As shown in FIG. 1, an example of this fabrication procedure commences with the evaporation and deposition of a sub-1 micron (e.g., a 100-500 nm) metal film on a silicon (Si) substrate 12 with a thermally grown oxide (SiO2) layer, which will serve as the growth substrate for the graphene film. In an alternative embodiment, a quartz (SiO2) substrate is used in place of the Si/SiO2 substrate as the insulating substrate.

The metal film can be formed of any transition metal that either catalyzes the dehydrogenation of hydrocarbons or has certain carbon solubility under elevated temperature, such as nickel, platinum, ruthenium and copper; in this embodiment, the metal is nickel (Ni). Nickel has been widely used for the synthesis of carbon nanotubes. Furthermore, nickel has a face-centered cubic structure and its face forms a triangular network of nickel atoms with lattice parameters similar to those of graphene. A protective oxide layer (e.g., nickel oxide) can be formed on the surface of the metal film, and the oxide layer can be removed before graphene formation by contacting it with hydrofluoric acid (HF), potassium hydroxide (KOH), or sodium hydroxide (NaOH).

FIG. 4 is an image of an as-deposited nickel film. FIG. 5 is an image of that nickel film after annealing is provided. FIG. 6 is an image of the annealed nickel film coated with a graphene layer.

FIGS. 7-10 illustrate the transfer of a few-layer graphene film from the nickel-coated substrate to a target substrate.

FIGS. 11-16 are optical images and atomic-force-microscopy characterizations of the few-layer graphene film on a Si/SiO2 substrate.

FIGS. 19-22 are high-resolution transmission-electron-microscope images illustrating the synthesized graphene films with various numbers of layers.

FIG. 31 shows optical images of graphene films after being transferred to SiO2/Si substrate

Saturday, January 30, 2010

Milestone Fusion Ignition in Sight with Gold Hohlraums Used to Contain Heavy Hydrogen Fuel for Fusion Reactions

A tiny chamber made of gold, called a hohlraum, is used to contain the pellet of heavy hydrogen fuel at the center of a fusion reaction at the National Ignition Facility. Laser beams enter through the two open ends of the hohlraum and are reflected in toward the fuel, heating it up to produce the fusion reaction.

After more than five decades of research, a major milestone toward the harnessing of fusion power is expected within the next year or two. This milestone, known as “fusion ignition,” should take place at an experimental facility built for that purpose in California. Known as the National Ignition Facility, or NIF, it started initial experiments last fall.

Researchers at MIT’s Plasma Science and Fusion Center (PSFC) have played an important part in making this pivotal event possible, and that role is outlined this week in a paper published in the journal Science. In a nutshell, they’ve figured out how to use a second fusion reaction as a kind of backlight, allowing them to see the details of what’s happening inside the primary reaction.

Fusion, the merging of two small atoms into one with a prodigious release of energy, is the process that powers the sun, and is seen as a potential long-term solution to the world’s energy needs because in principle it could supply vast amounts of energy without any greenhouse gas emissions. But the practical harnessing of this powerhouse is thought to remain decades away.

Achieving ignition would represent an important and long-sought step in that direction. One problem for the researchers and engineers trying to make it happen, though, is that the actual reactions would be taking place inside a 2-mm diameter fuel capsule whose temperature and pressure, as it implodes to 1/40 its initial diameter, become much greater than those at the very center of the sun. That’s not an easy environment for taking pictures, or any kind of measurements, in order to fine-tune the system to achieve the desired results.

An MIT team led by PSFC Senior Research Scientist Richard Petrasso developed the fusion backlighting method, which was described in a paper in Science in 2008. Now, the team is reporting in Science that they successfully used the method in a test facility at the University of Rochester, and were indeed able to learn important details about the nature of the electric and magnetic fields in and around this tiny capsule.

With the system they devised, “we’re taking a snapshot of what these electric and magnetic fields look like,” Petrasso says. “This is information is very difficult if not impossible to obtain any other way.”

Providing the ‘sparkplug’ for fusion

NIF uses an approach called indirect drive inertial fusion, in which the tiny capsule of heavy hydrogen fuel is centered inside a cavity called a hohlraum. Laser beams bombard the inside walls of the hohlraum, heating it and generating x-rays that cause the capsule to implode. Ignition, the goal of the NIF, means the point at which the energy released by some fusing atoms at the center of the capsule provides the “sparkplug” that causes other surrounding super-dense atoms to fuse, and so on, in a chain reaction. 

But to get to the point of ignition, Petrasso explains, diagnostic tools are needed to reveal the details of what actually happens inside the imploding pellet, where temperatures reach 200 million degrees Kelvin and the pressure can reach a trillion times atmospheric pressure. In order for the ignition to work, the capsule of deuterium and tritium — two heavy forms of the element hydrogen — must be nearly perfectly spherical, nearly perfectly placed at the center of the hohlraum cavity, and must implode in a nearly perfectly symmetrical way.

How much room for error is there in these parameters? That’s one of the things that remains to be determined, and that’s why ways of peering inside the system while it’s in action could play an important role, Petrasso says.

To do that, in these experiments at the Laboratory for Laser Energetics in Rochester, a second capsule was placed nearby and hit by another set of laser beams, producing a flash of protons to illuminate the first capsule, inside a hohlraum.

Nelson Hoffman, a plasma physicist at Los Alamos National Laboratory, says the MIT team has developed “several very effective ways” of measuring important aspects of what goes on inside the fusion capsules, which he says are essential to know “as an indicator of how close they are to the ignition goal.” He adds that as a result, the MIT team has already found surprising phenomena in the way the electric and magnetic fields are distributed.

“The quest to achieve fusion ignition is one of the hardest scientific problems ever tackled,” Hoffman says, “so looking at the problem with ‘new eyes,’ like MIT's proton radiographs, is crucial for detecting phenomena that don't show up any other way.”

In the results being reported this week, for example, the MIT team along with collaborators from Lawrence Livermore National Laboratory, the Laboratory for Laser Energetics, and General Atomics, saw results from one experiment that produced a striking “five-pronged, asterisk-like pattern” in the fields surrounding the imploding capsule. The pattern results from the positioning of the incoming laser beams — something that will require further analysis to understand its potential impact on fusion dynamics.

Petrasso expects that at NIF it will take many months from the beginning of the experiments until the point where ignition is achieved. “This has never been done before, so we need to rely in part on empirical knowledge as we bring the experiment up and create the precise conditions that are required,” says Petrasso, who has worked at the PSFC since 1978. “Many parts of this effort have a sound experimental and theoretical basis, and some less so. Because of this, we need to fill in those gaps, to get the conditions just right.” In addition to this work at the Rochester facility, MIT researchers including six doctoral students have had an ongoing role in the work at the NIF.

Not only could ignition be an important step toward perhaps making fusion power practical one day, he says, but it will certainly be an important scientific tool for better understanding how the sun and other stars work.

“You create conditions which you really only can find in the centers of stars,” he says, even though in these experiments those conditions only exist for a few billionths of a second. “Astrophysicists, for one, will find these conditions extremely interesting and compelling.”

Story by David L. Chandler, MIT News Office
 

DOE Loans Nissan $1.4 Billion to Retool Smyrna Plant to Build Advanced Electric Automobiles


U.S. Secretary of Energy Steven Chu announced  on January 28th  that the Department of Energy has closed its $1.4 billion loan agreement with Nissan North America, Inc. to retool their Smyrna, Tennessee factory to build advanced electric automobiles and an advanced battery manufacturing facility. The two projects are expected to create up to 1,300 American jobs and conserve up to 65.4 million gallons of gasoline per year – an amount equal to six times the oil spilled by the Exxon Valdez in 1989.

“This is an investment in our clean energy future. It will bring the United States closer to reducing our dependence on foreign oil and help lower carbon pollution,” said Secretary Chu. “We are committed to making strides to revitalize the American auto industry and supporting the development of clean energy vehicles.”

Nissan plans to use the proceeds from the loan to produce its all-electric vehicle, the LEAF, at its existing Smyrna, Tennessee plant. Nissan will offer electric vehicles to fleet and retail customers, and plans to ramp up production capacity in Smyrna up to 150,000 vehicles annually.

Nissan is pursuing a global strategy of transitioning to electric vehicles. Building a state-of-the-art manufacturing plant in Smyrna, to produce 200,000 battery packs annually, is a significant part of that strategy. Nissan is also laying the groundwork in developing an infrastructure in the US to support electric vehicles. The company has formed partnerships with states, counties, municipalities, and electric utilities to prepare markets for the introduction of electric vehicles including the installation of charging stations.

The announcement marks the third loan arrangement agreement signed by DOE with an advanced technology vehicle manufacturer.  In September 2009, DOE signed its first loan agreement for $5.9 billion to Ford Motor Company. Last week, DOE also signed a $465 million loan agreement with Tesla Motors, which will be used to build manufacturing facilities in California for electric power-trains and Tesla's Model S electric sedan. The Department has also signed a conditional commitment with Fisker Automotive to build plug-in hybrid electric vehicles. Tenneco, Inc. became the first advanced technology component manufacturer to obtain a conditional commitment from DOE in October of last year.

The Department was provided $7.5 billion for credit subsidy costs by Congress to cover up to $25 billion in direct loans to companies making cars and components in US factories that increase fuel economy at least 25 percent above 2005 fuel economy levels.
The agreement was negotiated and signed through the Department’s Loan Programs Office, which supports the development of innovative, advanced vehicle technologies to create thousands of clean energy jobs while helping reduce the nation’s dependence on foreign oil.

CEINT Collaboration to Elucidate Environmental Impacts of Nanomaterials


As researchers around the world hasten to employ nanotechnology to improve production methods for applications that range from manufacturing materials to creating new pharmaceutical drugs, a separate but equally compelling challenge exists.

History has shown that previous industrial revolutions, such as those involving asbestos and chloroflurocarbons, have had some serious environmental impacts. Might nanotechnology also pose a risk?

Linsey Marr and Peter Vikesland, faculty members in the Via Department of Civil and Environmental Engineering at Virginia Tech, are part of the national Center for the Environmental Implications of NanoTechnology (CEINT), funded by the National Science Foundation (NSF) in 2008. Along with Michael Hochella, University Distinguished Professor of Geosciences, they represent Virginia Tech’s efforts in a nine-member consortium awarded $14 million over five years, starting in 2008. Virginia Tech’s portion is $1.75 million.

CEINT is dedicated to elucidating the relationship between a vast array of nanomaterials — from natural, to manufactured, to those produced incidentally by human activities — and their potential environmental exposure, biological effects, and ecological consequences. It will focus on the fate and transport of natural and manufactured nanomaterials in ecosystems.

Headquartered at Duke University, CEINT is collaboration between Duke, Carnegie Mellon University, Howard University, and Virginia Tech as the core members, as well as investigators from the University of Kentucky and Stanford University. CEINT academic collaborations in the U.S. also include on-going activities coordinated with faculty at Clemson, North Carolina State, UCLA, and Purdue universities. At Virginia Tech, CEINT is part of the University’s Institute for Critical Technology and Applied Science (ICTAS).

Scientists and engineers at the center have outlined plans to conduct research on the possible environmental health impacts of nanomaterials. The plans include new approaches, such as creating a predictive toxicology model based on cell assays and building ecosystems to track nanoparticles.

Characterization of Airborne Particles

In one of the novel ways Marr is conducting her tests, she and her colleagues are growing human lung cells and placing them in chambers that leave the lung cell surface exposed to air. This placement allows for direct contact of the cells with aerosolized particles at the air-liquid interface (ALI). One of Marr’s post-doctoral researchers, Amara Holder, and colleagues from Berkeley have previously exposed the cells to particles in diesel exhaust and a methane flame. They compared the ALI exposure to conventional in vitro exposure, where particles are suspended in a liquid cell culture medium.

“Our findings showed the ALI exposure inhalation route is a relevant in vitro approach and is more responsive than the conventional exposure to particle suspensions,” they concluded. Now, Marr and her colleagues are repeating the exposure with engineered nanoparticles. The researchers will enhance the deposition of smaller particles by generating an electric field and “relying on the electrophoretic force to drive charged particles to the cell surface.”

“With this design, lung cells can be exposed to substantial numbers of aerosolized engineered nanoparticles, such as silver and metal oxides, as single particles rather than large agglomerates,” Marr explained. A challenge in tests of nanoparticles’ toxicity has been that very small particles like to form aggregates, so testing interactions of the smallest particles with cells requires special approaches.

Marr and one of her graduate students, Andrea Tiwari, have selected the C60 fullerene as a model for carbonaceous nanomaterials because of its relative simplicity, evidence of toxicity, and rich history in the scientific literature. The discovery of the C60 compound in 1985 earned Harold Kroto, James R. Heath, and Richard Smalley the 1996 Nobel Prize in Chemistry. C60 fullerenes and variations on them are being used throughout the nanotechnology industry.

“Airborne carbonaceous nanomaterials are likely to be found in production facilities and in ambient air and may exhibit toxic effects if inhaled,” Marr and Tiwari said. They further theorized that when exposed to the air, nanomaterials are likely to be chemically transformed after the exposure to oxidants in the atmosphere.

In their preliminary studies, results indicate that “oxidation does impact solubility, as absorbance after resuspending in water is lower for fullerenes exposed to ozone.” The implication is that reactions in the atmosphere can transform nanoparticles and make them more likely to dissolve in water once they deposit back to earth. There, they can travel farther and come in contact with more organisms than if they were stuck to soil.

To collect airborne nanoparticles for analysis, Marr’s group designed a low-cost thermophoretic precipitator that uses ice water as a cooling source and a 10-W resistor as the heating source. They flowed synthetic aerosols through the precipitator and used a transmission electron microscope to inspect the particles.

“Preliminary analysis confirmed that this precipitator was effective in collecting nanoparticles of a wide range of sizes and will be effective in future studies of airborne nanoparticles,” Marr said.

As her work in this field progresses, Marr was able to use her research in the characterization of airborne particle concentrations during the production of carbonaceous nanomaterials, such as fullerenes and carbon nanotubes, in a commercial nanotechnology facility. Based on the measurements of her study, done with Behnoush Yeganeh, Christy Kull and Mathew Hull, all graduate students, they concluded that engineering controls at the facility “appear to be effective in limiting exposure to nanomaterials,” and reported their findings in the American Chemical Society’s publication Environmental Science and Technology (Vol. 42, No. 12, 2008)

However, they point to the limitations of this initial study that focused mainly on the physical characterization, and which did not differentiate between particles generated by nanomaterial soot production and those from other sources.

Effects of Carboxylic Acids on nC60 Aggregate Formation

“The increasing production and application of the C60 fullerene due to its distinctive properties will inevitably lead to its release into the environment,” Marr’s colleague, Vikesland, said. Already, the biomedical, optoelectronics, sensors and cosmetics industries are among the users of the C60 fullerene.

“Little is currently known about the interaction of the C60 fullerene with the constituents of natural waters, and thus it is hard to predict the fate of C60 that is released into the natural environment,” Vikesland added. “The C60 fullerene is virtually insoluble in water.”

However, one of the components of natural water is natural organic matter (NOM). When the C60 fullerene is released in water, it forms “highly stable dispersed colloidal C60 aggregates or nC60,” Vikesland explained. These aggregates can exhibit significant disparities in aggregate structure, size, morphology, and surface charge and behave very differently than the C60 alone.

The problem with NOM is its randomness, resulting in diverse characteristics of the aggregates that form when they mix with the C60.

So, Vikesland is looking at small molecular weight carboxylic acids such as acetic acid, tartaric acid, and citric acid, all widely detected constituents of natural water and biological fluids. He and his graduate student Xiaojun Chang have specifically looked at the formation of nC60 in acetic acid (vinegar) solutions, subjected the aggregates to extended mixing, and found that the solution’s chemistry differs substantially from nC60 mixed in water alone.

“The citrate affects the formation of the nC60 in two ways,” Vikesland said. It alters the pH, a key factor in controlling the surface charge of nC60 and it directly interacts with the C60 surface.

Vikesland explained the significance of this result. When nC60 is produced in the presence of the carboxylic acids, its aggregates differ significantly from those produced without the acids. In general, Vikesland said, these aggregates have more negative surface charges and are more homogenous than those produced in water alone.

“These results suggest that the ultimate fate of C60 in aqueous environments is likely to be significantly affected by the quantities and types of carboxylic acids present in natural systems and by the solution pH,” Vikesland added. Furthermore, because carboxylic acids are common in biological fluids, Vikesland is interested in how his findings relate to the mechanisms by which C60 interact with cells in vivo.

These acids may significantly affect any conclusions ultimately reached regarding the impact of the C60 fullerene into the environment. His current work appears in an issue of Environmental Pollution v157, issue 4 (April 2009), pp. 1072-1080.

Risø DTU: New knowledge about the Deformation of Nanocrystals Offers New Tools for Nanotechnology


With new, advanced equipment, scientists at Risø DTU have shown that materials to produce micro-and nanocomponents react very differently depending on whether crystals are large or small. This research creates important knowledge that can be used to develop technologies aimed at the nanoproduction of micro-electro-mechanical systems such as digital microphones in mobile phones, miniature pressure sensors in water pumps and acceleration sensors in airbags.

The nanotechnology toolbox is expanding continuously and the material for nanocomponents is a chapter by itself, because materials at nanoscale often react quite differently than materials at large scale. Therefore it is necessary to know what happens when you squeeze, flatten and stamp out metals for nanocomponents. Otherwise, the finished component may not be functioning as it should.

Using transmission electron microscopy (TEM) and cooperating with research institutions in China and the USA, Risø DTU has looked into what happens when you deform crystals of nanosize from the metal titanium. At this scale the size of the titanium crystals determines the behaviour of the metal during mechanical treatment. Titanium crystals of a certain size are deformed in a way that each atom is systematically displaced in proportion to the neighbouring atoms, which results in a macroscopic deformation. This process is called 'deformation twinning'. When the titanium crystals become smaller, they are much more difficult to deform. However, this only applies to a certain lower limit.

When titanium crystals become smaller than 1 micrometer (0.001 mm), they are deformed in the same way as very large crystals. This kind of deformation is called 'dislocation plasticity'. The discovery has great significance for how to produce nanocomponents of metal and ceramics in order to obtain the desired properties in a final component.

With support from the Danish Council for Independent Research | the Danish Research Council for Nature and Universe (FNU), Risø National Laboratory for Sustainable Energy, DTU has acquired new, advanced equipment to study nanocrystals of metal while they are being deformed in an electron microscope. This equipment has recently been developed by the company Hysitron Incorporated in the USA. The new equipment allows scientists to study in very fine detail structural changes in the TEM while they, with great precision, can deform the metal crystals, and thereby obtain a detailed knowledge of the surprising new nano phenomena.

The results will provide the technologies for nano production with important new knowledge.

NanoUltra™ Super Hydrophilic Window Technology Targets $600 Million U.S. Pro Window Cleaning Market


Nanophase Technologies Corporation, a technology leader in the development of advanced nanoengineered products,  launched NanoUltra™ Super Hydrophilic Window Technology, their new line of architectural glass cleaning products, at the International Window Cleaning Association (IWCA) Convention in Reno, Nevada. The NanoUltra™ product line is targeted for the approximately $600 million U.S. professional window cleaning and restoration market which includes over 10,000 window cleaners.

"The introduction of NanoUltra™, our first commercial product family, dovetails perfectly into our business strategy of identifying an industry's unmet needs and taking the solutions directly to the end users within the industry," said Nanophase president and chief executive officer Jess Jankowski. "We couldn't be happier with today's product launch at an international convention showcasing state-of-the-art products for a large potential market, professional window cleaning and restoration. We are currently establishing our distribution channels and look forward to keeping our customers, shareholders and the financial community updated, as our NanoUltra™ sales and marketing campaign continues to unfold."

Nanophase vice president of sales and marketing David Nelson commented, "Architectural windows present an exciting new market with untapped potential for nano-based products. Our goal is to establish the technology in the professional industry and then expand into the consumer market which we believe also offers significant potential."

Nelson continued, "Our revolutionary NanoUltra™ product line gives professional window cleaners, window restoration specialists, and building managers the opportunity to provide the next generation of window cleaning technology that truly makes windows shine, while keeping them cleaner longer than traditional window washing."

In conjunction with the NanoUltra™ introduction, Nanophase launched a product-specific website, www.nano-ultra.com, to showcase the products and provide in-depth product information, including a list of distributors and their contact information.  

About NanoUltra™ Super Hydrophilic Window Technology
NanoUltra™ Super Hydrophilic Window Technology keeps windows cleaner longer than traditional window washing by providing an invisible protection to the surface of glass. The NanoUltra™ products impart a protection to the glass surface that is hydrophilic, allowing water to create a sheeting action that washes away dirt and grime. These revolutionary products also accelerate drying time, resulting in virtually spot and streak free windows.

This high-performance product works using a two-step application method. First, NanoUltra™ Super Hydrophilic Window Pretreatment, a nano cerium oxide based product, is applied to provide both a chemical and mechanical polishing mechanism that restores glass to ‘like new' condition. Then the NanoUltra™ Super Hydrophilic Treatment product is applied to maintain the super hydrophilic surface property and give windows the ultimate shine.

The results can provide significant benefits to building owners and managers, professional window cleaners and window restoration specialists. In addition to potentially reducing liability and cleaning costs for the building owners, the NanoUltra™ technology offers up-sell and new business development opportunities for those servicing these patrons.

About Nanophase Technologies
Nanophase Technologies Corporation (Nasdaq:NANX), www.nanophase.com, is a leader in nanomaterials technologies and provides nanoengineered products and solutions for multiple industrial product applications. Using a platform of patented and proprietary integrated nanomaterial technologies, the Company creates products with unique performance attributes from two ISO 9001:2000 and ISO 14001 facilities. Nanophase delivers commercial quantity and quality nanoparticles, coated nanoparticles, and nanoparticle dispersions in a variety of media. 

Applied Nanotech Holdings Expands Presence in Solar Energy Field with Arima Eco Energy


Applied Nanotech Holdings, Inc. (Austin, Texas) entered into an agreement with Arima Eco Energy Technologies Corporation of Taiwan (ArimaEco), a world leader in concentrated photovoltaic (CPV) module development, system integration, and installation with systems deployed in Asia and Europe.  The agreement was announced on January 27th.

CPV systems utilizing multi-junction solar cells offer the highest efficiency of commercially available solar technology. As part of the collaboration between the two companies, ANI will take advantage of the high thermal diffusivity and low CTE of CarbAl™ material to further improve the efficiency and lifetime of CPV systems by increasing the sun concentration, reducing solar cell temperatures, limiting temperature fluctuations, and reducing thermal stresses caused by different rates of thermal expansion.
As part of the agreement, ANI will also represent ArimaEco CPV systems in the State of Texas on an exclusive basis. Working with ArimaEco, ANI intends to implement its concept of “energy fields” by combining the existing land and infrastructure for capturing wind energy in Texas with high efficiency and low cost CPV solar energy systems. This will enable wind energy fields to transform to higher value renewable energy fields, combining both wind and solar power generation. CPV solar energy is extremely well suited to Texas, given the sunny climate, pre-existing wind farms, and transmission infrastructure.

ANI will introduce the ArimaEco CPV module at the Photovoltaic World Pavilion at the Renewable Energy World Conference and Expo in Austin TX, February 23-25 along with CarbAl™ material.

“We are optimistic about the collaboration with ANI and we are looking forward to further the implementation of CPV solar energy in Texas by integrating both companies’ capabilities and resources,” said Mr. Howard Chou, Sales and Marketing Manager of ArimaEco.

“I am confident that ArimaEco CPV systems will benefit from our nanotechnological tailored CarbAlTM  material for improved thermal management,” said Dr. Zvi Yaniv, President and CEO of Applied Nanotech, Inc.

“It is part of our strategic direction to become closer to the end product user and be less reliant on others for revenue generation and commercialization of our technology,” said Doug Baker, CEO of Applied Nanotech Holdings, Inc. “I am pleased that we have entered into this relationship with ArimaEco.  This strengthens our position in the renewable energy field and complements our funded projects related to the development of technical inks for the solar energy market.”

ABOUT APPLIED NANOTECH HOLDINGS, INC.
Applied Nanotech Holdings, Inc. (OTC BB: APNT)is a premier research and commercialization organization focused on solving problems at the molecular level. Its team of PhD level scientists and engineers work with companies and other organizations to solve technical impasses and create innovations that will create a competitive advantage. The business model is to license patents and technology to partners that will manufacture and distribute products using the technology. Applied Nanotech has over 250 patents or patents pending. Applied Nanotech's website is www.appliednanotech.net.

ABOUT ARIMA ECO TECHNOLOGIES CORPORATION
ArimaEco is a leading CPV system integrator and total solution provider in the sector of CPV solar energy. ArimaEco's high concentration photovoltaic (HCPV) modules have passed indoor tests under IEC62108 standards and obtained compliance certification in 2008. Currently ArimaEco is one among the very few global CPV players that has CPV power plant design and installation experience. ArimaEco's vision is to be a HCPV system total solution provider offering a better solution for solar energy and help users to create more value by implementing CPV technology. ArimaEco's website is www.arimaeco.com.

Alexander Graham Bell Meets Nanotechnology: Photoacoustic Spectroscopy and Quantum Dots Used for Remote Detection of Explosives and Chemical Weapons


Commercial explosives and dangerous chemicals often contain taggants that allow the materials to be easily identified.  However terrorists don’t use such chemical markers.  Nano-Proprietary, Inc has developed a remote photoacoustic/quantum dot method to detect terror weapons even if a barrier is present.

One of the specific photoacoustic methods capable of detecting outgassed by-products or vapors of explosive materials is photoacoustic spectroscopy (PAS). Initially discovered by Alexander Graham Bell in 1880, this method was further developed theoretically by Rosencwaig and Gersho in 1973. Now Nano-Proprietary, Inc. (Austin, TX)  has developed a PAS system that uses quantum dots for the remote detection of explosives and dangerous chemicals.  The system is capable of detecting the vapors from explosive materials from a safe distance, according to Dr. Zvi Yaniv, President and CEO of Applied Nanotech, Inc in U.S. Patent Application 20100022009Nano-Proprietary, Inc. is a subsidiary of Applied Nanotech Holdings Inc.

The idea behind the photoacoustic effect is based on the detection of sound waves produced by a gas surrounding an object which absorbs the light from a light source modulated by amplitude. The object can be in a solid state, liquid, or gas phase.

Yaniv devised strategies for chemically sensing explosives, chemical weapons, and other harmful agents by exploiting the high vapor pressures that many of them possess and the emission of nitrogen- and phosphorus-containing free radicals from the explosives, chemical weapons, and other harmful agents. This is the case for phosphorus-containing chemical nerve agents like sarin, soman, tabun, and VX and for nitro-containing explosives like trinitrotoluene (TNT) and nitroglycerine. Chemical sensing, such as utilizing spectral characteristics, could be used to detect such harmful materials in public places like airports, subways, shopping malls, etc. This would allow for the pre-emptive identification of harmful materials, before they have inflicted any damage.

FIG. 1 illustrates, in general terms,  Applied Nanotech’s  process of using nanoparticles for chemical sensing; detection and monitoring of an environment. Photoacoustic techniques have a number of advantages such as a very strong signal-to-noise ratio, and can be tuned to very specifically detect the explosive materials with sensitivities in the range of about 1 part per million (ppm) to approximately 1 part per billion (ppb) in certain situations such as for plastic explosives.
FIG. 2 depicts a photoacoustic detection system useful for remote sensing of chemical and hazardous materials. The photoacoustic system comprises a light source 201 that passes through a chopper 202 and into a photoacoustic cell 203 comprising the analyte gas. Pressure waves within the cell are detected as sound waves by microphones 204. The signal produced by the microphones can then be amplified and transmitted to a remote location, typically via a wireless means.
Nanoparticle-Based Detection

The process uses nanometer-size particles (also known as nanoparticles or nanocrystals, in the sensing and identification of chemicals and harmful agents by exposing such chemicals and harmful agents to the nanoparticles. Such exposure could be in the gas phase, the liquid phase, or the solid phase, and could include mixed phase exposures. Such sensing exploits unique properties of the nanoparticles, specifically unique photoluminescence properties of the nanoparticles known as quantum dots.

Nanoparticle, are particles comprising finite bandgap materials, and having particle diameters which are generally less than about 100 nm. Finite bandgap materials, in contrast to zero bandgap and infinite bandgap materials, can be categorized as semimetals, semiconductors, insulators, and combinations thereof. Examples of finite bandgap materials include, but are not limited to, silicon (Si), gallium arsenide (GaAs), cadmium sulfide (CdS), cadmium selenide (CdSe), titanium dioxide (TiO.sub.2), diamond, cerium oxide (CeO2), silicon oxide (SiO2), aluminum oxide (Al2O3), and the like and combinations thereof.

Photoluminescence (PL) comprises all forms of luminescence including fluorescence, phosphorescence, and combinations thereof. The excitation radiation, which induces photoluminescence, is typically in the ultraviolet (UV) region of the electromagnetic (EM) spectrum, but can generally be in any or all regions of the electromagnetic spectrum capable of inducing photoluminescence in the nanoparticles. Photoluminescence is typically in the visible (optical) region of the electromagnetic spectrum, but can generally be in any or all regions of the electromagnetic spectrum.

Photoluminescence of the nanoparticles, in the process,  is induced when the nanoparticles are irradiated with light, particularly with wavelengths found in the UV region of the electromagnetic spectrum. The emitted radiation (the photoluminescence) is generally in the visible (optical) region of the electromagnetic spectrum. When a chemical species adsorbs onto the surfaces of the nanoparticles, the photoluminescence properties of the nanoparticles are altered. Chemical sensing is accomplished by detecting and  analyzing the altered photoluminescence properties. Sensing includes detecting, analyzing, monitoring, and the like and combinations thereof.

Harmful materials could be detected by spraying a suspect item (e.g., luggage or mail) with an aerosol of nanoparticles (e.g., silicon nanoparticles) having one or more pre-defined altered photoluminescence properties, illuminating the suspect item with a UV laser in the process of spraying it with the aerosol of nanoparticles, measuring the photoluminescence shift or change, i.e., measuring the altered photoluminescence properties, and observing whether or not there is a pre-defined shift or change in the photoluminescence spectra corresponding to a known--and already evaluated--chemical agent (sarin, for example), i.e., comparing the altered photoluminescence properties to the one or more pre-defined altered photoluminescence properties.

Such a process could be carried out remotely from a distance. In the case of sarin, the high vapor pressure of this nerve agent might render the environment in the immediate vicinity of the article to be relatively high in sarin content-even if it were enclosed in some type of crude container that permitted the escape of merely trace amounts. The sarin vapor would then cause a predetermined shift or change in the photoluminescence spectra of the nanoparticles on account of the altered chemical environment. A variation on this embodiment would be to use the nanoparticle aerosol in the vicinity of a military weapons depot, whereby leaks in containers containing explosives and chemical weapons could be detected and identified.

The use of such photoacoustic processes in such  remote sensing applications can have numerous variations. For example, in some embodiments, a photoacoustic detector is installed in location of interest and then the signal is wirelessly transmitted to a remote location when a certain gas/species is detected. In some or other embodiments, if wireless transmission is prohibited due to certain limitations in the field or in the area of interest, a tunable UV laser can interrogate the photoacoustic cavity from a large distance by tuning the laser to specific well-defined frequencies with which the photoacoustic effect can be triggered and a specific gas identified. Devices using the photoacoustic effect in such a way can be easily miniaturized, and one can envision portability and even distribution of the device to individual soldiers in the field. In some or other such embodiments, in a way that is somewhat analogous to the way microwaves are used,

 Applicants believe that this photoacoustic phenomena can be used without a dedicated cavity by shining an infra-red (IR) laser on an area of interest and then trying to listen to the specific acoustic effect with the help of special remotely-located microphones. Further, by shining a laser beam for a dedicated gas on an area of interest and comparing it to the beam reflected from an area in the vicinity that does not contain the specific gas in question and then comparing the two reflected beams, the presence of the harmful gas can be detected and the signal-to-noise ratio can be increased.