Coloradoan Hillary Cavanaugh, with slight irony, called it the best powder she’d ever seen.

Using a plastic garbage can, Kathy Kay filled an industrial dumpster with it.

The “it” is decades-old tufts of insulation ripped out of the walls and ceilings of a home in a modest neighborhood in southern Durham. Five miles away, a second group of Pratt student volunteers tore sheet rock out of a two-story home or removed anything that wasn’t nailed down in five other homes, including a wooden back deck.

More than 30 Pratt students worked a good part of a recent “Sledgehammer Saturday” preparing empty homes for renovation or relocation to a low-income neighborhood. This, and subsequent such Saturdays, may also be small steps toward a new experience for students wanting to incorporate into their education hands-on experience making existing homes greener and more energy efficient.

The Sledgehammer Saturday, as well as its November 21 sequel, was organized by Builders of Hope, a non-profit organization that renovates abandoned and boarded-up homes and makes them available for sale to low-income families. The homes are either renovated in their neighborhoods, or more likely moved to other areas to create neighborhoods of “recycled” homes. The group frequently recruits volunteer groups – like the Duke engineering students – to assist their own professionals.

While alone a worthy effort to help the community, a handful of Duke faculty members and staff saw in the activities of Builders of Hope a unique learning opportunity. Like a counterpoint to the Smart Home Program, where students designed from scratch and now tinker in a home with all the latest green technologies, working with Builders of Hope could provide students real-world experiences in sustainability and energy efficiency.

“The Smart Home is a fantastic educational facility, however it’s not like the housing most people live in,” said Pratt’s David Schaad, associate professor of the practice. “In our discussions, we quickly recognized that we really don’t have a vehicle for getting students first-hand experience in understanding how to make conventional homes more efficient. We could see for example students performing energy audits, implementing actions based on the findings, and then measuring their effectiveness.”

Discussions are ongoing between Builders of Hope, the Pratt School of Engineering and the Nicholas School of the Environment about possibly working together on a new educational experience. Those involved in these early discussions are Schaad, Jim Gaston, Smart Home Program director; and Nicholas professors Lincoln Pratson and Jonathan Weiner.

“Duke and Builders of Hope are very much interested in the possibility of collaborating in a way that provides one or more new, hands-on learning opportunities for Duke students,” Pratson said. “The volunteer weekends are an easy and immediate way to engage students in Builders of Hope projects while we pursue developing other activities in the projects with educational content.

“For example, each home Builders of Hope renovates has its own set of particular problems,” Pratson continued. “There could be a home that is a huge energy sink. It would be a great opportunity for students to figure out how the energy is being wasted and design solutions to the problem.”

After their first encounter with Duke students, Builders of Hope officials were impressed with the spirit of the volunteers.

“The students are such good workers — they worked hard and stayed on task, just as you expect from engineers,” said Emily Egge, director of development for Builders of Hope and on-site at the insulation removal. “They worked with speed and diligence. They shifted gears without complaint – when they originally signed up it was supposed to be a more of painting and landscaping day. But, just like in most projects, things change.”

John Jenkins, Builders of Hope coordinator at the second site, added with a chuckle, “The students were great – especially when they’re tearing up stuff like sheetrock. I guess it relieves some tension. It’s funny though, they didn’t seem to go after the cleaning up with the same vigor as they went at the walls with sledgehammers.”

Duke University bioengineers have developed a simple and inexpensive method for loading cancer drug payloads into nano-scale delivery vehicles and demonstrated in animal models that this new nanoformulation can eliminate tumors after a single treatment. After delivering the drug to the tumor, the delivery vehicle breaks down into harmless byproducts, markedly decreasing the toxicity for the recipient.

Nano-delivery systems have become increasingly attractive to researchers because of their ability to efficiently get into tumors. Since blood vessels supplying tumors are more porous, or leaky, than normal vessels, the nanoformulation can more easily enter and accumulate within tumor cells. This means that higher doses of the drug can be delivered, increasing its cancer-killing abilities while decreasing the side effects associated with systematic chemotherapy.

“When used to deliver anti-cancer medications in our models, the new formulation has a four-fold higher maximum tolerated dose than the same drug by itself, and it induced nearly complete tumor regression after one injection,” said Ashutosh Chilkoti, Theo Pilkington Professor of Biomedical Engineering at Duke’s Pratt School of Engineering. “The free drug had only a modest effect in shrinking tumors or in prolonging animal survival.”

The results of Chilkoti’s experiments were published early online in the journal Nature Materials.

“Just as importantly, we believe, is the novel method we developed to create these drugs,” Chilkoti said. “Unlike other approaches, we can produce large quantities simply and inexpensively, and we believe the new method theoretically could be used to improve the effectiveness of other existing cancer drugs.”

Central to the new method is how the drug is “attached” to its polypeptide delivery system and whether or not a drug can be dissolved in water.

The delivery system makes use of the bacterium Escherichia coli (E. coli) which has been genetically altered to produce a specific artificial polypeptide known as a chimeric polypeptide. Since E. coli are commonly used to produce proteins, it makes for a simple and reliable production plant for these specific polypeptides with high yield.

When attached to one of these chimeric polypeptides, the drug takes on characteristics that the drug alone does not possess.  Most drugs do not dissolve in water, which limits their ability to be taken in by cells. But being attached to a nanoparticle makes the drug soluble.

“When these two elements are combined in a container, they spontaneously self-assemble into a water-soluble nanoparticle,” Chilkoti said. “They also self-assemble consistently and reliably in a size of 50 nanometers or so that makes them ideal for cancer therapy. Since many chemotherapeutic drugs are insoluble, we believe that this new approach could work for them as well.”

The latest experiments involved doxorubicin, a commonly used agent for the treatment of cancers of the blood, breast, ovaries and other organs. The researchers injected mice with tumors implanted under their skin with either the chimeric polypeptide-doxorubicin combination or doxorubicin alone.

The mice treated with doxorubicin alone had an average tumor size 25 times greater than those treated with the new combination. The average survival time for the doxorubicin-treated mice was 27 days, compared to more than 66 days for mice getting the new formulation.

The Duke researchers now plan to test the new combination on different types of cancer, as well as tumors growing within different organs. They will also try combining these chimeric polypeptides with other insoluble drugs and test their effectiveness against tumors.

The research was supported by the National Institutes of Health. Other Duke team members were Mingnan Chen, Jonathan McDaniel, Wenge Liu, J. Andrew Simnick, and J. Andrew MacKay, now at the University of Southern California.

Energy harvesting is the process of converting one form of energy, such as motion, into another form of energy, in this case electricity. Strategies range from the development of massive wind farms to produce large amounts of electricity to using the vibrations of walking to power small electronic devices.

Although motion is an abundant source of energy, only limited success has been achieved because the devices used only perform well over a narrow band of frequencies. These so-called “linear” devices can work well, for example, if the character of the motion is fairly constant, such as the cadence of a person walking. However, as researchers point out, the pace of someone walking, as with all environmental sources, changes over time and can vary widely.

“The ideal device would be one that could convert a range of vibrations instead of just a narrow band,” said Samuel Stanton, graduate student in Duke’s Pratt School of Engineering, working in the laboratory of Brian Mann, assistant professor of mechanical engineering and materials sciences. The team, which included undergraduate Clark McGehee, published the results of their latest experiments early online in Applied Physics Letters.

“Nature doesn’t work in a single frequency, so we wanted to come up with a device that would work over a broad range of frequencies,” Stanton said. “By using magnets to ‘tune’ the bandwidth of the experimental device, we were able verify in the lab that this new non-linear approach can outperform conventional linear devices.”

Although the device they constructed looks deceptively simple, it was able to prove the team’s theories on a small scale. It is basically a small cantilever, several inches long and a quarter inch wide, with an end magnet that interacts with nearby magnets. The cantilever base itself is made of a piezoelectric material, which has the unique property of releasing electrical voltage when it is strained.

The key to the new approach involved placing moveable magnets of opposing poles on either side of the magnet at the end of the cantilever arm. By changing the distance of the moveable magnets, the researchers were able to “tune” the interactions of the system with its environment, and thus produce electricity over a broader spectrum of frequencies.

“These results suggest to us that this non-linear approach could harvest more of the frequencies from the same ambient vibrations,” Mann said. “More importantly, being able to capture more of the bandwidth makes it more likely that these types of devices could someday rival batteries as a portable power source.”

The range of applications for non-linear energy harvesters varies widely. For example, Mann is working on a project that would use the motion of ocean waves to power an array of sensors that would be carried inside ocean buoys.

“These non-linear systems are self-sustaining, so they are ideal for any electrical device that needs batteries and is in a location that is difficult to access,” Mann said.

For example, the motion of walking could provide enough electricity to power an implanted device, such as a pacemaker or cardiac defibrillator. On a larger scale, sensors in the environment or spacecraft could be powered by the everyday natural vibrations around them, Mann said.

Mann’s research is supported by the Office of Naval Research.

According to Duke University engineers, the answer is “jumping” water droplets. As it turns out, the same phenomenon that occurs when it’s time for certain mushrooms to eject spores also occurs when dew droplets skitter across a surface that is highly water repellant, or superhydrophobic.

Using a specially designed high-speed camera and microscope set-up, the engineers for the first time captured the actions of tiny water droplets on a man-made superhydrophobic surface, and to their surprise found that the droplets literally jumped straight up and off the surface.

Simply put, when two tiny water droplets – whether on a mushroom’s spore or on a water-repellent surface – meet to form a larger drop, enough energy is released in the formation of the new droplet to cause it to “jump” off the surface.

“This spontaneous jumping is powered by the surface energy released when droplets coalesce,” said Jonathan Boreyko, a third-year graduate student at Duke’s Pratt School of Engineering, who works in the laboratory of Assistant Professor Chuan-Hua Chen. “Because this process involves very tiny droplets at high speeds, no one had captured this phenomenon before.”  Watch Boreyko explain phenomenon.

The results of the team’s experiments were published early online in the journal Physics Review Letters.

“A similar phenomenon occurs with the ejection of spores, known as ballistospores, from certain kinds of mushrooms,” Boreyko said. “When a drop of water condensate at the base of the spore comes into contact with the wetted spore, it triggers the propulsion of the spore into the air.”

Chen and Boreyko’s research is the first known engineering reproduction of the ballistospore ejection process.

The work also has immediate applications in energy harvesting and thermal management, Chen said. For example, the spontaneous jumping motion offers an internal mechanism, independent of gravity, to remove condensate from the condensers in power plants.

The superhydrophobic surface used by the researchers is characterized by rows and rows of tiny bumps, covered with even tinier hairs projecting upward. When a water droplet lands on this type of surface, it only touches the ends of the tiny hairs. This creates pockets of air underneath the droplet that keeps it from touching the surface. This cushion of air keeping the droplet aloft is much like a puck in an air-hockey game. The same principle allows water striders to skim along the surface of ponds without falling into the water, Chen said.

“When two of these condensate drops coalesce into one, they jump at very high speeds,” Boreyko said. “They move as fast as one meter per second. By taking a side view of the phenomenon, we can plainly see the droplets jump. You wouldn’t see it looking down on the surface.”

Interestingly, the researchers found that the mechanism used to eject ballistospores is almost identical. The critical size of the droplet on the spore for the jumping to occur is the same as that on the man-made superhydrophobic surface, and spores “jump” off the mushroom at about the same speed.

Chen said knowing how superhydrophobic surfaces are able to repel condensate drops could lead to improvements in many types of systems where heat needs to be removed through condensation.

“Smaller water droplets are much more efficient at transferring heat,” Chen explained. “With the jumping mechanism, the average droplet size is about one hundred times smaller.

“In conventional cooling systems, as in big industrial plants, condensate must be removed using external forces for continuous operation,” Chen said. “One of the main benefits of this superhydrophobic surface is that it needs no external energy – the coalescing of the droplets provides all the energy needed to remove the condensate.”

Chen’s research is supported by the National Science Foundation. Jonathan Boreyko is supported by the Pratt-Gardner Fellowship.

Now, almost one thousand years since Zhou Dunyi wrote these lines in China, scientists finally understand how the plant keeps itself clean and dry. It took an ultra high speed camera, a powerful microscope and an audio speaker to unlock a secret that has puzzled scientists for ages.

The process of solving this biological problem inspired Duke University engineers to make use of man-made surfaces resembling the lotus to improve the efficiency of modern engineering systems, such as power plants or electronic equipment, which must be cooled by removing heat through water evaporation and condensation.

For the first time, scientists were able to observe water as it condensed on the leaf’s surface, and more importantly, how the water condensate left the leaf.

The trick lies in the surface of the plant’s large leaves, and the subtle vibrations of nature. The leaves are covered with tiny irregular bumps spiked with even tinier hairs projecting upward. When a water droplet lands on this type of surface, it only touches the ends of the tiny hairs. The droplet is buoyed by air pockets below and ultimately is repelled off the leaf.

“We faced a tricky problem – water droplets that fall on the leaf easily roll off, while condensate that grows from within the leaf’s nooks and crannies is sticky and remains trapped,” said Jonathan Boreyko, a third-year graduate student at Duke’s Pratt School of Engineering, who works in the laboratory of assistant professor Chuan-Hua Chen. The results of the team’s experiments were published early on-line in the journal Physics Review Letters. Watch Boreyko explain the phenomenon.

“Scientists and engineers have long wondered how these sticky drops are eventually repelled from the leaf after their impalement into the tiny projections,” Boreyko said. “After bringing lotus leaves into the lab and watching the condensation as it formed, we were able to see how the sticky drops became unsticky.”

The key was videotaping the process while the lotus leaf rested on top of the woofer portion of a stereo speaker at low frequency. Condensation was created by cooling the leaf. It turned out that after being gently vibrated for a fraction of a second, the sticky droplets gradually unstuck themselves and jumped off the leaf.

Voila, a dry leaf.

“This solves a long-standing puzzle in the field,” Chen said. “People have observed that condensation forms every night on the lotus leaf. When they come back in the morning the water is gone and the leaf is dry. The speaker reproduced in the lab what happens every day in nature, which is full of subtle vibrations, especially for the lotus, which has large leaves atop long and slender stems.”

The results of these experiments, as well as earlier ones showing for the first time that water droplets spontaneously “jump” off a highly water-repellent, or superhydrophobic, surface, will allow engineers to employ man-made surfaces much like the lotus leaf in settings where the removal of condensation and the transfer of heat are necessary.

We have revealed the physics behind anti-dew superhydrophobicity, a vital property for water-repellent materials to be deployed in the real world,” Chen said. “These materials will be used in humid or cold environments where condensation will naturally occur. Our findings point to a new direction to develop water-repellent materials that would survive in demanding natural environments, and have strong implications for a variety of engineering applications including non-sticking textiles, self-cleaning optics and drag-reducing hulls.”

Chen’s research is supported by Pratt startup funds.

Alas, some bacteria apparently have an individualistic streak that makes them zig when the others zag.

A new set of experiments by Duke University bioengineers has uncovered the existence of “bistability,” in which an individual cell has the potential to live in either of two states, depending on which state it was in when stimulated.

Taking into account the effects of this phenomenon should greatly enhance the future efficiency of synthetic circuits, said biomedical engineer Lingchong You of Duke’s Pratt School of Engineering and the Duke Institute for Genome Sciences & Policy.

In principle, re-programmed bacteria in a synthetic circuit can be useful for producing proteins, enzymes or chemicals in a coordinated way, or even delivering different types of drugs or selectively killing cancer cells, the scientists said.

Researchers in this new field of synthetic biology “program” populations of genetically altered bacteria to direct their actions in much the same way that a computer program directs a computer. In this analogy, the genetic alteration is the software, the cell the computer. The Duke researchers found that not only does the software drive the computer’s actions, but the computer in turn influences the running of the software.

“In the past, synthetic biologists have often assumed that the components of the circuit would act in a predictable fashion every time and that the cells carrying the circuit would just serve as a passive reactor,” You said. “In essence, they have taken a circuit-centric view for the design and optimization process. This notion is helpful in making the design process more convenient.”

But it’s not that simple, say You and his graduate student Cheemeng Tan, who published the results of their latest experiments early online in the journal Nature Chemical Biology.

“We found that there can be unintended consequences that haven’t been appreciated before,” said You. “In a population of identical cells, some can act one way while others act in another. However, this process appears to occur in a predictable manner, which allows us to take into account this effect when we design circuits.”

Bistability is not unique to biology. In electrical engineering, for example, bistability describes the functioning of a toggle switch, a hinged switch that can assume either one of two positions – on or off.

“The prevailing wisdom underestimated the complexity of these synthetic circuits by assuming that the genetic changes would not affect the operation of the cell itself, as if the cell were a passive chassis,” said Tan. “The expression of the genetic alteration can drastically impact the cell, and therefore the circuit.

“We now know that when the circuit is activated, it affects the cell, which in turn acts as an additional feedback loop influencing the circuit,” Tan said. “The consequences of this interplay have been theorized but not demonstrated experimentally.”

The scientists conducted their experiments using a genetically altered colony of the bacteria Escherichia coli (E.coli) in a simple synthetic circuit. When the colony of bacteria was stimulated by external cues, some of the cells went to the “on” position and grew more slowly, while the rest went to the “off” position and grew faster.

“It is as if the colony received the command not to expand too fast when the circuit is on,” Tan explained. “Now that we know that this occurs, we used computer modeling to predict how many of the cells will go to the ‘on’ or ‘off’ state, which turns out to be consistent with experimental measurements”

The experiments were supported by the National Science Foundation, the National Institutes of Health and a David and Lucille Packard Fellowship. Duke’s Philippe Marguet was also a member of the research team.

DARPA is interested in such a device because it could offer military commanders in the field valuable information about which soldiers are likely to become sick and potentially unfit for duty.

The project, under the direction of Geoffrey Ginsburg, MD, PhD, director of the IGSP’s Center for Genomic Medicine, is being conducted by a broad and experienced team of investigators including Christopher Woods, MD, MPH; and Aimee Zaas, MD, MPH, from Duke’s Division of Infectious Disease; Lawrence Carin, PhD, from Duke’s Pratt School of Engineering; and Alfred Hero, PhD, from the University of Michigan’s College of Engineering.

Using advanced genomic and statistical tools, investigators have already made considerable progress.

In the first phase of the project, researchers discovered a genomic “signature” of infection — a set of changes in gene expression that occurred in people who became symptomatic after exposure to a rhinovirus, the influenza A virus, or the respiratory syncytial virus.

They found that in some cases, those changes became apparent hours or even days before symptoms arose.

Biomedical engineers in Duke’s Pratt School of Engineering have already designed a prototype of the device that can “read” the genomic signatures of infection.

Over the next two years, in the second phase of the study, researchers will refine the probe and further validate the genomic signature of infections by additional pathogens, including the seasonal H1N1 virus.

Some of those studies will include human viral challenge studies already underway at Retroscreen Virology, Ltd., in London, U.K. Other viral challenge studies are contemplated later in the program in the United States.

One aspect of the research focuses on the natural history of viral infections among college students living in close quarters.

This fall, investigators are enrolling Duke students in freshman dormitories in a study of the onset and spread of upper respiratory infections, including influenza. Participants will use a special website to file daily reports about their health and provide blood and other specimens as needed.

Investigators hope to enroll from 500 to 800 students and follow them for the entire academic year.

“We expect to gather valuable data about the novel H1N1 virus from these studies,” says Ginsburg. “Presymptomatic detection of a cold or flu would be a significant advance in maintaining the health of our troops and will certainly be a breakthrough for the public’s health and well being, as well.”

Collaborators in the project include researchers at the University of Wisconsin, the University of Virginia, and the National Center for Genome Resources in New Mexico.

Duke University computer engineers have made use of standard cell phone features – accelerometers, cameras and microphones – to turn the unique properties of a particular space into a distinct fingerprint. While standard global positioning systems (GPS) are only accurate to 10 meters (32 feet) and do not work indoors, the new application is designed to work indoors and can be as precise as telling if a user is on one side of an interior wall or another.

The system, dubbed SurroundSense, uses the phone’s built-in camera and microphone to record sound, light and colors, while the accelerometer records movement patterns of the phone’s user. This information is sent to a server, which knits the disparate information together into a single fingerprint.

“You can’t tell much from any of the measurements individually, but when combined, the optical, acoustic and motion information creates a unique fingerprint of the space,” said Ionut Constandache, graduate student in computer science. He presented the details of SurroundSense at the 15th International Conference on Mobile Computing and Networking in Bejing on Sept. 25.

For example, in a bar, people spend little time moving and most time sitting, while the room is typically dark and noisy. In contrast, a Target store will be brightly lit with vibrant colors – especially red – with movement up and down aisles. SurroundSense can tell these differences.

Students of Romit Roy Chouhury, Duke assistant professor of electrical and computer engineering and senior member of the research team, fanned out across Durham, N.C. with their cell phones, collecting data in different types of businesses. So that they would not bias the measurements, the students “mirrored” the actions of selected customers.

“We went to 51 different stores and found that SurroundSense achieved an average accuracy of about 87 percent when all of the sensing capabilities were used,” Constandache said.

As more people use the application, it gets “smarter.”

“As the system collects and analyzes more and more information about a particular site, the fingerprint becomes that much more precise,” said Roy Choudhury. “Not only is the ambience different at different locations, but also can be different at different times at the same location.”

SurroundSense collects data at different time points, so it would be able to distinguish a Starbucks store at the morning rush when there are many customers from the slower period in mid-afternoon.

“We believe that SurroundSense is an early step toward a long-standing challenge of improving indoor localization,” Roy Choudhury said.

Currently, in order for the phone to collect data, it must be held with the camera facing down, though the researchers are working on strategies for the application to work if the phone is in a pocket, case or handbag. However, as the researchers pointed out, phones are now coming onto the market that are worn on the wrist or around the neck on a necklace.

As in many technical advances, it appears that batteries can be an Achilles’ heel. The Duke researchers are now considering the tradeoffs between having the application “on” all the time, which drains the battery faster, or having it take measurements at regular intervals. They are also trying to determine whether the entire application should be housed on the server, the phone, or some combination of the two.

Roy Choudhury’s research is supported by the National Science Foundation, Nokia, Verizon and Microsoft Research. Duke undergraduate Martin Azizyan also participated in the project.

However, little is known which particles may be harmful. Part of the problem is determining exactly what a nanoparticle is.

A new analysis by an international team of researchers from the Center for the Environmental Implications of NanoTechnology (CEINT), based at Duke University, argues for a new look at the way nanoparticles are selected when studying the potential impacts on human health and the environment. They have found that while many small particles are considered to be “nano,” these materials often do not meet full definition of having special properties that make them different from conventional materials.

Under the prevailing definition, a particle is deemed nano if its diameter is between 1 and 100 nanometers (nm) – about 1/10,000 the diameter of a human hair – and if it has properties that significantly differ from its naturally occurring, or bulk, counterpart.

The special properties of nanoparticles come from their high surface-area-to-volume ratio. They also have a considerably higher percentage of atoms on their surface compared to bulk particles, which can make them more reactive. These man-made materials can be found in a vast array of consumer products, including paints and sunscreens, as well as in water treatment plants and drug delivery systems.

For most of this decade, discussions of nanoparticles have tended to focus more on their size than their properties. However, after reviewing the scientific literature, the Duke-led team believes that the old definition is not specific enough. A definition that focuses on properties is critical, they say, to help scientists determine which particular nanoparticles are the most likely to represent a threat to the environment or human health.

Generally speaking, it is the very smallest particles (less than 30 nanometers) that should receive the most attention in studying the environmental and human health impacts of nanomaterials, according to Mark Wiesner, a Duke professor of civil and environmental engineering and director of the federally funded CEINT.

“There are an infinite number of potential new man-made nanoparticles, so we need to find a way to narrow our efforts to those that have the greatest likelihood of having the unique properties with unique effects,” Wiesner said.

“A key question to be answered is whether or not a particular nanoparticle has toxic or hazardous properties that are truly different from identical particles in their bulk form,” Wiesner continued. “This question has not been answered. To do so, we need to be speaking the same language when assessing any unique properties of these novel materials.”

The results of Wiesner’s analysis were published online in the journal Nature Nanotechnology. The study was supported by CEINT, which is jointly funded by the National Science Foundation and Environmental Protection Agency.

Specifically, the researchers found that nanoparticles approaching the 100 nm end of the size spectrum tend to have fewer special properties when compared to their bulk counterparts. Furthermore, they found that nanoparticles smaller than 30 nm tend to exhibit the unique properties that should command increased scrutiny, Wiesner said.

“Many nanoparticles smaller than 30 nanometers undergo drastic changes in their crystalline structure that enhance how the atoms on their surface interact with the environment,” Wiesner said.

For example, because of the increased surface-area-to-volume ratio, nanoparticles can be highly reactive with other chemicals in the environment and can also disrupt certain activities within cells.

“While there have been reports of nanoparticle toxicity increasing as the size decreases, it is still uncertain whether this increase in reactivity is harmful to the environment or human safety,” Wiesner said. “To settle this issue, toxicological studies should contrast particles that exhibit novel size-dependant properties, particularly concerning their surface reactivity, and those particles that do not exhibit these properties.”

Other members of the research team include Melanie Auffan, Duke; Jerome Rose and Jean-Yves Bottero, Aix-Marseille Universite, France; Gregory Lowry, Carnegie Mellon University; and Jean-Pierre Jolivet, Laboratoire de Chimie de la Matiere Condensee de Paris, France.

This time, it was the U.S. Green Building Council (USGBC), who announced this week that the Duke program is one of the recipients of its Excellence in Green Building Curriculum Recognition Awards for 2009.

Duke’s Smart Home Program was one of five award winners in the category covering colleges and universities. The award recognizes innovative green building curricula at all levels of education and provides financial support for promising new programs

“The Duke Smart Home Program continues to grow and attract students interested in smart technology and sustainable lifestyles,” said  Jim Gaston, Duke Smart Home Program director. “It is exciting to see students connect with industry and the community to develop innovative solutions that utilize new technologies. This award for excellence by the USGBC confirms that Duke is at the forefront of the green movement.”

Now in its second year, the USGBC initiative is a central component of its commitment to identify and disseminate innovative green building curricula to educators across the country.

“Through this initiative, USGBC is recognizing those organizations that are taking the lead in the development of innovative green building knowledge and resources,” said Rebecca Flora, USGBC senior vice president for education & research. “The extraordinary rise in green building in recent years has accelerated the need for relevant and engaging educational programs, and all of our participating organizations are playing an active role in helping USGBC meet this important need.”

Recognition Awards honor existing green building education projects, activities or programs, and includes a $1,000 honorarium

The centerpiece of Duke’s program is the Home Depot Smart Home, which is a 10-person student residence hall for green living and learning. Completed in 2007, the home is the world’s first LEED Platinum live-in laboratory. Students can participate in the program in a variety of ways: independent study for credit, house courses focused on sustainability topics, as senior capstone design projects, and as members of the Smart Home student club.

Primarily focused on undergraduates, the program encourages students from different academic disciplines to form teams and explore ways to use technology in the home. Smart Home Project students are encouraged to explore new technologies that aren’t being addressed through commercially available technology.

The USGBC awards were judged on demonstrated success, ability to be replicated, the scope of influence, advancement of green principles within the educational community and the fostering of a collaborative or interdisciplinary approach. The USGBC is made up of  78 local affiliates, more than 20,000 member companies and organizations, and more than 131,000 LEED accredited professionals.

Buildings in the U.S. are responsible for 39 percent of CO2 emissions, 40 percent of energy consumption, 13 percent of water consumption and 15 percent of GDP per year, according to the USGBC, which means that greater building efficiency can meet 85 percent of future U.S. demand for energy, and a national commitment to green building has the potential to generate 2.5 million American jobs.