OREGON STATE UNIVERSITY

college of engineering

Oregon State launches humanitarian engineering program

CORVALLIS, Ore. - The Oregon State University College of Engineering has recently launched a humanitarian engineering program like few others in the nation, partly as a response to a growing number of students who want to make an impact both locally and globally.

Undergraduate students can now minor in this field, taking classes that emphasize the importance of socio-cultural, economic, environmental and resource management factors. Work in ethics, social justice and cross-cultural communication is also part of the program.

Humanitarian engineering emphasizes science and engineering-based solutions that help to improve the human condition, access to basic human needs, the quality of life or level of community resilience. OSU’s program is one of only a few in the nation based in an academic curriculum.

The program reflects an engaged concept of service and the university’s historic land grant mission, officials say. Through it, students will explore case studies of development projects and a historic perspective on humanitarian interventions.

One OSU student who understands that concept is Grace Burleson, a graduating senior majoring in mechanical engineering. She grew up as a missionary child and was raised by parents with a passion for helping underserved populations.

“When I got to college, I loved my engineering coursework but never got excited by applying it to things like cars or computers,” said Burleson. “I began research in humanitarian engineering and landed an internship in Uganda, working where I developed a sustainable business plan for the construction, distribution and maintenance of BioSand water filters.”                    

As a formalized academic program, humanitarian engineering will contribute to the effort of the OSU College of Engineering to become a recognized model as an inclusive and collaborative community.

“The program is attracting a more diverse group of prospective students than is typically attracted to engineering, including women,” said mechanical engineering professor Kendra Sharp, who directs the program, and was appointed the first Richard and Gretchen Evans Professor in Humanitarian Engineering.

OSU is also one of just 10 universities nationwide to offer a Peace Corps Master’s International program in engineering. The university was the first in Oregon to join this initiative, which allows graduate students in several disciplines to get a master’s degree while doing a full 27-month term of service in the Peace Corps.

Multiple student organizations, including Oregon State’s award-winning Engineers Without Borders chapter and the American Society of Civil Engineering student chapter, have also been working on water, energy and other projects in the developing world. 

“Students at Oregon State receive an accredited engineering degree, so adding on this minor opens many more doors and perspectives with how we look at engineering,” said Burleson. “It creates a gateway for really exciting and impactful projects.”

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Krista Klinkhammer, 541-737-4416

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Kendra Sharp, 541-737-5246

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Thousands of landslides in Nepal earthquake raise parallels for Pacific Northwest

CORVALLIS, Ore. – Research teams have evaluated the major 7.8 magnitude subduction zone earthquake in Gorkha, Nepal, in April 2015, and identified some characteristics that may be of special relevance to the future of the Pacific Northwest.

Most striking was the enormous number and severity of landslides.

Many people understand the damage that can be caused to structures, roads, bridges and utilities by ground shaking in these long-lasting types of earthquakes, such as the one that’s anticipated on the Cascadia Subduction Zone between northern California and British Columbia.

But following the Nepal earthquake – even during the dry season when soils were the most stable – there were also tens of thousands of landslides in the region, according to reconnaissance team estimates. In their recent report published in Seismological Research Letters, experts said that these landslides caused pervasive damage as they buried towns and people, blocked rivers and closed roads.

Other estimates, based on the broader relationship between landslides and earthquake magnitude, suggest the Nepal earthquake might have caused between 25,000 and 60,000 landslides.

The subduction zone earthquake expected in the future of the Pacific Northwest is expected to be larger than the event in Nepal.

Ben Mason, a geotechnical engineer and assistant professor in the College of Engineering at Oregon State University, was a member of the Geotechnical Extreme Event Reconnaissance team that explored the Nepal terrain. He said that event made clear that structural damage is only one of the serious threats raised by subduction zone earthquakes.

“In the Coast Range and other hilly areas of Oregon and Washington, we should expect a huge number of landslides associated with the earthquake we face,” Mason said. “And in this region our soils are wet almost all year long, sometimes more than others. Each situation is different, but soils that are heavily saturated can have their strength cut in half.”

Wet soils will also increase the risk of soil liquefaction, Mason said, which could be pervasive in the Willamette Valley and many areas of Puget Sound, Seattle, Tacoma, and Portland, especially along the Columbia River.

Scientists have discovered that the last subduction zone earthquake to hit the Pacific Northwest was in January 1700, when – like now - soils probably would have been soggy from winter rains and most vulnerable to landslides.

The scientific study of slope stability is still a work in progress, Mason said, and often easier to explain after a landslide event has occurred than before it happens. But continued research on earthquake events such as those in Nepal may help improve the ability to identify areas most vulnerable to landslides, he said. Models can be improved and projections made more accurate.

“If you look just at the terrain in some parts of Nepal and remove the buildings and people, you could think you were looking at the Willamette Valley,” Mason said. “There’s a lot we can learn there.”

In Nepal, the damage was devastating.

Landslides triggered by ground shaking were the dominant geotechnical effect of the April earthquake, the researchers wrote in their report, as slopes weakened and finally gave way. Landslides caused by the main shock or aftershocks blocked roads, dammed rivers, damaged or destroyed villages, and caused hundreds of fatalities.

The largest and most destructive event, the Langtang debris avalanche, began as a snow and ice avalanche and gathered debris that became an airborne landslide surging off a 500-meter-tall cliff. An air blast from the event flattened the forest in the valley below, moved 2 million cubic meters of material and killed about 200 people.

Surveying the damages after the event, Mason said one of his most compelling impressions was the way people helped each other.

“Nepal is one of the poorest places, in terms of gross domestic product, that I’ve ever visited,” he said. “People are used to adversity, but they are culturally rich. After this event it was amazing how their communities bounced back, people helped treat each other’s injuries and saved lives. As we make our disaster plans in the Pacific Northwest, there are things we could learn from them, both about the needs for individual initiative and community response.”

Aside from landslides, many lives were lost in collapsing structures in Nepal, often in homes constructed of rock, brick or concrete, and frequently built without adequate enforcement of building codes, the report suggested. Overall, thousands of structures were destroyed. There are estimates that about 9,000 people died, and more than 23,000 were injured. The earthquake even triggered an avalanche on Mount Everest that killed at least 19 people.

The reconnaissance effort in Nepal was made possible by support from the National Science Foundation, the U.S. Geological Survey, the U.S. Agency for International Development, the OSU College of Engineering, and other agencies and universities around the world.

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Ben Mason, 541-737-2014

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Nepal landslide

Tooth fillings of the future may incorporate bioactive glass

CORVALLIS, Ore. – A few years from now millions of people around the world might be walking around with an unusual kind of glass in their mouth, and using it every time they eat.

Engineers at Oregon State University have made some promising findings about the ability of “bioactive” glass to help reduce the ability of bacteria to attack composite tooth fillings – and perhaps even provide some of the minerals needed to replace those lost to tooth decay.

Prolonging the life of composite tooth fillings could be an important step forward for dental treatment, the researchers say, since more than 122 million composite tooth restorations are made in the United States every year. An average person uses their teeth for more than 600,000 “chews” a year, and some studies suggest the average lifetime of a posterior dental composite is only six years.

The new research was just published in the journal Dental Materials, in work supported by the National Institutes of Health.

“Bioactive glass, which is a type of crushed glass that is able to interact with the body, has been used in some types of bone healing for decades,” said Jamie Kruzic, a professor and expert in advanced structural and biomaterials in the OSU College of Engineering.

“This type of glass is only beginning to see use in dentistry, and our research shows it may be very promising for tooth fillings,” he said. “The bacteria in the mouth that help cause cavities don’t seem to like this type of glass and are less likely to colonize on fillings that incorporate it. This could have a significant impact on the future of dentistry.”

Bioactive glass is made with compounds such as silicon oxide, calcium oxide and phosphorus oxide, and looks like powdered glass. It’s called “bioactive” because the body notices it is there and can react to it, as opposed to other biomedical products that are inert. Bioactive glass is very hard and stiff, and it can replace some of the inert glass fillers that are currently mixed with polymers to make modern composite tooth fillings.

“Almost all fillings will eventually fail,” Kruzic said. “New tooth decay often begins at the interface of a filling and the tooth, and is called secondary tooth decay. The tooth is literally being eroded and demineralized at that interface.”

Bioactive glass may help prolong the life of fillings, researchers say, because the new study showed that the depth of bacterial penetration into the interface with bioactive glass-containing fillings was significantly smaller than for composites lacking the glass.

Fillings made with bioactive glass should slow secondary tooth decay, and also provide some minerals that could help replace those being lost, researchers say. The combination of these two forces should result in a tooth filling that works just as well, but lasts longer.

Recently extracted human molars were used in this research to produce simulated tooth restoration samples for laboratory experiments. OSU has developed a laboratory that’s one of the first in the world to test simulated tooth fillings in conditions that mimic the mouth.

If this laboratory result is confirmed by clinical research, it should be very easy to incorporate bioactive glass into existing formulations for composite tooth fillings, Kruzic said.

The antimicrobial effect of bioactive glass is attributed, in part, to the release of ions such as those from calcium and phosphate that have a toxic effect on oral bacteria and tend to neutralize the local acidic environment.

“My collaborators and I have already shown in previous studies that composites containing up to 15 percent bioactive glass, by weight, can have mechanical properties comparable, or superior to commercial composites now being used,” Kruzic said.

This work was done in collaboration with researchers from the School of Dentistry at the Oregon Health & Science University and the College of Dental Medicine at Midwestern University.

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Jamie Kruzic, 541-737-7027

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Bioactive glass

Photonic “sintering” may create new solar, electronics manufacturing technologies

CORVALLIS, Ore. – Engineers at Oregon State University have made a fundamental breakthrough in understanding the physics of photonic “sintering,” which could lead to many new advances in solar cells, flexible electronics, various types of sensors and other high-tech products printed onto something as simple as a sheet of paper or plastic.

Sintering is the fusing of nanoparticles to form a solid, functional thin-film that can be used for many purposes, and the process could have considerable value for new technologies.

Photonic sintering has the possible advantage of higher speed and lower cost, compared to other technologies for nanoparticle sintering.

In the new research, OSU experts discovered that previous approaches to understand and control photonic sintering had been based on a flawed view of the basic physics involved, which had led to a gross overestimation of product quality and process efficiency.

Based on the new perspective of this process, which has been outlined in Nature Scientific Reports, researchers now believe they can create high quality products at much lower temperatures, at least twice as fast and with 10 times more energy efficiency.

Removing constraints on production temperatures, speed and cost, the researchers say, should allow the creation of many new high-tech products printed onto substrates as cheap as paper or plastic wrap.

“Photonic sintering is one way to deposit nanoparticles in a controlled way and then join them together, and it’s been of significant interest,” said Rajiv Malhotra, an assistant professor of mechanical engineering in the OSU College of Engineering. “Until now, however, we didn’t really understand the underlying physics of what was going on. It was thought, for instance, that temperature change and the degree of fusion weren’t related – but in fact that matters a lot.”

With the concepts outlined in the new study, the door is open to precise control of temperature with smaller nanoparticle sizes. This allows increased speed of the process and high quality production at temperatures at least two times lower than before. An inherent “self-damping” effect was identified that has a major impact on obtaining the desired quality of the finished film.

“Lower temperature is a real key,” Malhotra said. “To lower costs, we want to print these nanotech products on things like paper and plastic, which would burn or melt at higher temperatures. We now know that is possible, and how to do it. We should be able to create production processes that are both fast and cheap, without a loss of quality.”

Products that could evolve from the research, Malhotra said, include solar cells, gas sensors, radiofrequency identification tags, and a wide range of flexible electronics. Wearable biomedical sensors could emerge, along with new sensing devices for environmental applications.

In this technology, light from a xenon lamp can be broadcast over comparatively large areas to fuse nanoparticles into functional thin films, much faster than with conventional thermal methods. It should be possible to scale up the process to large manufacturing levels for industrial use.

This advance was made possible by a four-year, $1.5 million National Science Foundation Scalable Nanomanufacturing Grant, which focuses on transcending the scientific barriers to industry-level production of nanomaterials. Collaborators at OSU include Chih-hung Chang, Alan Wang and Greg Herman.

OSU researchers will work with two manufacturers in private industry to create a proof-of-concept facility in the laboratory, as the next step in bringing this technology toward commercial production.

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Discovery could open door to frozen preservation of tissues, whole organs

CORVALLIS, Ore. – Researchers in the College of Engineering at Oregon State University have discovered a new approach to “vitrification,” or ice-free cryopreservation, that could ultimately allow a much wider use of extreme cold to preserve tissues and even organs for later use.

The findings were announced today in PLOS ONE, in work supported by the National Science Foundation.

“This could be an important step toward the preservation of more complex tissues and structures,” said Adam Higgins, an associate professor in the OSU School of Chemical, Biological and Environmental Engineering, and expert on medical bioprocessing.

Cryopreservation has already found widespread use in simpler applications such as preserving semen, blood, embryos, plant seeds and some other biological applications. But it is often constrained by the crystallization that occurs when water freezes, which can damage or destroy tissues and cells, Higgins said. This is similar to what happens to some food products when they are stored in a freezer, and lose much of their texture when thawed.

To address this, researchers have used various types of cryoprotectants that help reduce cell damage during the freezing process – among them is ethylene glycol, literally the same compound often used in automobile radiators to prevent freezing.

A problem, Higgins said, is that many of these cryoprotectants are toxic, and can damage or kill the very cells they are trying to protect from the forces of extreme cold.

In the new OSU research, the engineers developed a mathematical model to simulate the freezing process in the presence of cryoprotectants, and identified a way to minimize damage. They found that if cells are initially exposed to a low concentration of cryoprotectant and time is allowed for the cells to swell, then the sample can be vitrified after rapidly adding a high concentration of cryoprotectants. The end result is much less overall toxicity, Higgins said.

The research showed that healthy cell survival following vitrification rose from about 10 percent with a conventional approach to more than 80 percent with the new optimized procedure.

“The biggest single problem and limiting factor in vitrification is cryoprotectant toxicity, and this helps to address that,” Higgins said. “The model should also help us identify less toxic cryoprotectants, and ultimately open the door to vitrification of more complex tissues and perhaps complete organs.”

If that were possible, many more applications of vitrification could be feasible, especially as future progress is made in the rapidly advancing field of tissue regeneration, in which stem cells can be used to grow new tissues or even organs.

Tissues could be made in small amounts and then stored until needed for transplantation. Organs being used for transplants could be routinely preserved until a precise immunological match was found for their use. Conceptually, a person could even grow a spare heart or liver from their own stem cells and preserve it through vitrification in case it was ever needed, Higgins said.

Important applications might also be found in new drug development.

Drug testing is now carried out with traditional cell culture systems or animal models, which in many cases don’t accurately predict the effect of the drug in humans. To address this, researchers are developing “organs-on-a-chip,” or microfluidic chambers that contain human cells cultured under conditions that mimic native tissues or organs.

These new “organ-on-a-chip” systems may be able to more accurately predict drug responses in humans, but to deploy them, cells must be preserved in long-term storage. The new research could help address this by making it possible to store the systems in a vitrified state.

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Adam Higgins, 541-737-6245

Storage advance may boost solar thermal energy potential

CORVALLIS, Ore. – Engineers at Oregon State University have identified a new approach for the storage of concentrated solar thermal energy, to reduce its cost and make it more practical for wider use.

The advance is based on a new innovation with thermochemical storage, in which chemical transformation is used in repeated cycles to hold heat, use it to drive turbines, and then be re-heated to continue the cycle. Most commonly this might be done over a 24-hour period, with variable levels of solar-powered electricity available at any time of day, as dictated by demand.

The findings have been published in ChemSusChem, a professional journal covering sustainable chemistry. The work was supported by the SunShot Initiative of the U.S. Department of Energy, and done in collaboration with researchers at the University of Florida.

Conceptually, all of the energy produced could be stored indefinitely and used later when the electricity is most needed. Alternatively, some energy could be used immediately and the rest stored for later use.

Storage of this type helps to solve one of the key factors limiting the wider use of solar energy – by eliminating the need to use the electricity immediately. The underlying power source is based on production that varies enormously, not just night and day, but some days, or times of day, that solar intensity is more or less powerful. Many alternative energy systems are constrained by this lack of dependability and consistent energy flow.

Solar thermal electricity has been of considerable interest because of its potential to lower costs. In contrast to conventional solar photovoltaic cells that produce electricity directly from sunlight, solar thermal generation of energy is developed as a large power plant in which acres of mirrors precisely reflect sunlight onto a solar receiver. That energy has been used to heat a fluid that in turn drives a turbine to produce electricity.

Such technology is appealing because it’s safe, long-lasting, friendly to the environment and produces no greenhouse gas emissions. Cost, dependability and efficiency have been the primary constraints.

“With the compounds we’re studying, there’s significant potential to lower costs and increase efficiency,” said Nick AuYeung, an assistant professor of chemical engineering in the OSU College of Engineering, corresponding author on this study, and an expert in novel applications and use of sustainable energy.

“In these types of systems, energy efficiency is closely related to use of the highest temperatures possible,” AuYeung said. “The molten salts now being used to store solar thermal energy can only work at about 600 degrees centigrade, and also require large containers and corrosive materials. The compound we’re studying can be used at up to 1,200 degrees, and might be twice as efficient as existing systems.

“This has the potential for a real breakthrough in energy storage,” he said.

According to AuYeung, thermochemical storage resembles a battery, in which chemical bonds are used to store and release energy – but in this case, the transfer is based on heat, not electricity.

The system hinges on the reversible decomposition of strontium carbonate into strontium oxide and carbon dioxide, which consumes thermal energy. During discharge, the recombination of strontium oxide and carbon dioxide releases the stored heat. These materials are nonflammable, readily available and environmentally safe.

In comparison to existing approaches, the new system could also allow a 10-fold increase in energy density – it’s physically much smaller and would be cheaper to build.

The proposed system would work at such high temperatures that it could first be used to directly heat air which would drive a turbine to produce electricity, and then residual heat could be used to make steam to drive yet another turbine.

In laboratory tests, one concern arose when the energy storage capacity of the process declined after 45 heating and cooling cycles, due to some changes in the underlying materials. Further research will be needed to identify ways to reprocess the materials or significantly extend the number of cycles that could be performed before any reprocessing was needed, AuYeung said.

Other refinements may also be necessary to test the system at larger scales and resolve issues such as thermal shocks, he said, before a prototype could be ready for testing at a national laboratory.

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Nick AuYeung, 541-737-4600

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“Spring-mass” technology heralds the future of walking robots

CORVALLIS, Ore. – A study by engineers at Oregon State University suggests that they have achieved the most realistic robotic implementation of human walking dynamics that has ever been done, which may ultimately allow human-like versatility and performance.

The system is based on a concept called “spring-mass” walking that was theorized less than a decade ago, and combines passive dynamics of a mechanical system with computer control. It provides the ability to blindly react to rough terrain, maintain balance, retain an efficiency of motion and essentially walk like humans do.

As such, this approach to robots that can walk and run like humans opens the door to entire new industries, jobs and mechanized systems that do not today exist.

The findings on spring-mass walking have been reported for the first time in IEEE Transactions on Robotics, by engineers from OSU and Germany. The work has been supported by the National Science Foundation, the Defense Advanced Research Projects Agency and the Human Frontier Science Program.

The technologies developed at OSU have evolved from intense studies of both human and animal walking and running, to learn how animals achieve a fluidity of motion with a high degree of energy efficiency. Animals combine a sensory input from nerves, vision, muscles and tendons to create locomotion that researchers have now translated into a working robotic system.

The system is also efficient. Studies done with their ATRIAS robot model, which incorporates the spring-mass theory, showed that it’s three times more energy-efficient than any other human-sized bipedal robots.

“I’m confident that this is the future of legged robotic locomotion,” said Jonathan Hurst, an OSU professor of mechanical engineering and director of the Dynamic Robotics Laboratory in the OSU College of Engineering.

“We’ve basically demonstrated the fundamental science of how humans walk,” he said.

“Other robotic approaches may have legs and motion, but don’t really capture the underlying physics,” he said. “We’re convinced this is the approach on which the most successful legged robots will work. It retains the substance and science of legged animal locomotion, and animals demonstrate performance that far exceeds any other approach we’ve seen. This is the way to go.”

The current technology, Hurst said, is still a crude illustration of what the future may hold. When further refined and perfected, walking and running robots may work in the armed forces. As fire fighters they may charge upstairs in burning buildings to save lives. They could play new roles in factories or do ordinary household chores.

Aspects of the locomotion technology may also assist people with disabilities, the researchers said.

“Robots are already used for gait training, and we see the first commercial exoskeletons on the market,” said Daniel Renjewski, the lead author on the study with the Technische Universitat Munchen. “However, only now do we have an idea how human-like walking works in a robot. This enables us to build an entirely new class of wearable robots and prostheses that could allow the user to regain a natural walking gait.” 

There are few limits to this technology, the researchers said.

“It will be some time, but we think legged robots will enable integration of robots into our daily lives,” Hurst said. “We know it is possible, based on the example of animals. So it’s inevitable that we will solve the problem with robots. This could become as big as the automotive industry.”

And much of this, the scientists said, will be based on the “spring-mass” concept, which animals have been perfecting through millions of years of evolution. 

The robots being constructed at OSU were designed to mimic this “spring-legged” action of bipedal animals. With minor variations, muscles, tendons and bones form a structure that exhibits most of the required behavior, and conscious control just nudges things a little to keep it going in the right direction. The effort is smooth and elastic, and once understood, can be simulated in walking robots by springs and other technology.

ATRIAS, the human-sized robot most recently created at OSU, has six electric motors powered by a lithium polymer battery about the size of a half-gallon of milk, which is substantially smaller than the power packs of some other mobile robots. It can take impacts and retain its balance. It can walk over rough and bumpy terrain.

Researchers said in their new study that this technology “has the potential to enhance legged robots to ultimately match the efficiency, agility and robustness of animals over a wide variety of terrain.”

In continued research, work will be done to improve steering, efficiency, leg configuration, inertial actuation, robust operation, external sensing, transmissions and actuators, and other technologies.

Other collaborators in the development of this technology have included Jessy Grizzle at the University of Michigan and Hartmut Geyer at Carnegie Mellon University. Scientific work on the motion of animals was done with Monica Daley at the Royal Veterinary College, which guided the robot’s development.

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Jonathan Hurst, 541-737-7010

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A YouTube video is available of the walking robot: http://bit.ly/1HQKqOZ


Walking robot
Walking robot

Methodology could lead to more sustainable manufacturing systems

CORVALLIS, Ore. – Engineers at Oregon State University have developed a new “sustainable development methodology” to help address a social and regulatory demand for manufacturing processes that more effectively consider their economic, environmental and social impacts.

The work was recently published in the Journal of Cleaner Production. It outlines a way to help designers and manufacturing engineers carefully consider all the ramifications of their design decisions, and to evaluate the possible different ways that a product could be built – before it ever hits the assembly line.

“There’s a lot of demand by consumers, workers and companies who want to make progress on the sustainability of products and manufacturing processes,” said Karl Haapala, an associate professor in the OSU College of Engineering.

“There’s usually more than one way to build a part or product,” he said. “With careful analysis we can identify ways to determine which approach may have the least environmental impact, lowest cost, least waste, or other advantages that make it preferable to a different approach.”

This movement, researchers say, evolved more than 20 years ago from an international discussion at the United Nations Conference on Environment and Development, which raised concerns about the growing scarcity of water, depletion of non-renewable sources of energy, human health problems in the workplace, and other issues that can be linked to unsustainable production patterns in industry.

The challenge, experts say, is how to consider the well-being of employees, customers, and the community, all while producing a quality product and staying economically competitive. It isn’t easy, and comprehensive models that assess all aspects of sustainability are almost nonexistent.

“With current tools you can analyze various aspects of an operation one at a time, like the advantages of different materials, transportation modes, energy used, or other factors,” Haapala said. “It’s much more difficult to consider all of them simultaneously and come out with a reasonable conclusion about which approach is best.”

To aid that effort, OSU researchers created a new methodology that incorporates unit process modeling and an existing technique called life-cycle inventory. This allowed them to quantify a selected set of sustainability metrics, and ask real-world questions. Should the product use a different material? Would running the production line faster be worth the extra energy used or impact on worker health and safety? Which approach might lead to injuries and more lost work? How can scrap and waste be minimized? Which design alternative will generate the least greenhouse gas emissions?

To illustrate this approach in the study, the researchers used three hypothetical “bevel gear” alternatives, a common part produced in the aircraft and automotive industry. Their six-step system considered energy consumption, water use, effluent discharge, occupational health and safety, operating cost, and other factors to evaluate the use of different materials and manufacturing processes  – and ultimately concluded through mathematical modeling which of three possible designs was the most sustainable.

"When you make decisions about what is best, you may make value judgements about what aspect of sustainability is most important to you,” Haapala said. “But the modeling results have the potential to assist designers in performing those evaluations and in understanding the tradeoffs alongside other aspects of the manufacturing process.”

This work was supported by the Boeing Company and the Oregon Metals Initiative.

This assessment approach, when further researched and tested, should be applicable to a wide range of products during the design decision-making process, researchers said in the study.

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Karl Haapala, 541-737-3122

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Mechanically joined bevel gear

Microchannel systems could boost future of solar thermal electricity

CORVALLIS, Ore. – Microchannel technology pioneered at Oregon State University has demonstrated in laboratory experiments that it can significantly improve the efficiency of solar thermal generation of electricity, which could lower costs and lead to a wider deployment of solar energy.

Based on this, and to help bring the technology to a practical test in the field, the U.S. Department of Energy SunShot Initiative today announced a $2.5 million award to OSU and five collaborating partners.

The recent findings are important, researchers say, because they could help make solar thermal electricity more cost-competitive with other forms of electricity generation and expand the number of locations able to host a solar thermal plant. The technology is also safe, long-lasting, friendly to the environment and produces no greenhouse gas emissions.

In contrast to conventional solar photovoltaic cells that produce electricity directly from sunlight, solar thermal generation of energy is developed as a large power plant in which acres of mirrors precisely reflect sunlight onto a solar receiver. At the solar receiver a fluid such as supercritical carbon dioxide is heated to a high temperature, which in turn is used as a heat source for an electricity generating facility.

Existing plants so far have been built in areas with the most consistent solar resource, such as the American Southwest. But if costs are lowered and efficiency improved, usage in general should expand, and other sunny areas in temperate or tropical zones around the world could develop such systems.

“Our advances could open the door to a significant, 15 percent higher efficiency for solar thermal technology,” said Kevin Drost, an associate professor of mechanical engineering, now retired, at Oregon State University, which is leading the research consortium working to develop these systems.

“We’re confident that this work will meet the goals being set by the Department of Energy,” Drost said. “With their support we’ll now move it beyond the laboratory toward a technology that could be commercialized."

A key to the advances is microchannel technology that has been developed at OSU in recent years, and is already finding applications in systems such as blood dialysis or advanced heat exchangers.

These microchannel systems use extremely small channels and a branching distribution system that speed the transfer process and improve efficiency. A microchannel lamination technology developed at OSU helps control cost, and short channels help control pressure.

“Solar thermal technology has to work at very high temperatures and very high pressures, which present special challenges,” Drost said. “We are demonstrating that microchannel systems, as well as the use of supercritical carbon dioxide as a heat transfer fluid, should meet those challenges.”

The use of supercritical carbon dioxide, the researchers said, is an important component of their system, in contrast to the molten salts now used for heat transfer. It can operate at 650-720 degrees centigrade, compared to 500 degrees for molten salt. The use of supercritical carbon dioxide will improve efficiency, use a much smaller turbine, and will help to eliminate the need for water cooling towers, a special concern in some of the sunny, dry locations where such energy plants are likely to be located.

The microchannel receiving panels using the supercritical carbon dioxide are also about four times smaller than existing technology, which reduces cost, loss of thermal energy and weight.

Collaborators on this project include Sandia National Laboratory, Pacific Northwest National Lab, the National Energy Technology Lab, University of California, Davis, and ECOKAP Technologies.

The U.S. Department of Energy SunShot Initiative is a collaborative national effort to make solar energy fully cost-competitive with traditional energy sources before the end of the decade.

Through SunShot, the Energy Department supports efforts by private companies, universities, and national laboratories to drive down the cost of solar electricity to $0.06, or six cents per kilowatt-hour.

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Brian Paul, 541-737-7320

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Solar thermal plant
Solar thermal power plant

“Quantum dot” technology may help light the future

CORVALLIS, Ore. – Advances at Oregon State University in manufacturing technology for “quantum dots” may soon lead to a new generation of LED lighting that produces a more user-friendly white light, while using less toxic materials and low-cost manufacturing processes that take advantage of simple microwave heating.

The cost, environmental, and performance improvements could finally produce solid state lighting systems that consumers really like and help the nation cut its lighting bill almost in half, researchers say, compared to the cost of incandescent and fluorescent lighting.

The same technology may also be widely incorporated into improved lighting displays, computer screens, smart phones, televisions and other systems.

A key to the advances, which have been published in the Journal of Nanoparticle Research, is use of both a “continuous flow” chemical reactor, and microwave heating technology that’s conceptually similar to the ovens that are part of almost every modern kitchen.

The continuous flow system is fast, cheap, energy efficient and will cut manufacturing costs. And the microwave heating technology will address a problem that so far has held back wider use of these systems, which is precise control of heat needed during the process. The microwave approach will translate into development of nanoparticles that are exactly the right size, shape and composition.

“There are a variety of products and technologies that quantum dots can be applied to, but for mass consumer use, possibly the most important is improved LED lighting,” said Greg Herman, an associate professor and chemical engineer in the OSU College of Engineering.

“We may finally be able to produce low cost, energy efficient LED lighting with the soft quality of white light that people really want,” Herman said. “At the same time, this technology will use nontoxic materials and dramatically reduce the waste of the materials that are used, which translates to lower cost and environmental protection.”

Some of the best existing LED lighting now being produced at industrial levels, Herman said, uses cadmium, which is highly toxic. The system currently being tested and developed at OSU is based on copper indium diselenide, a much more benign material with high energy conversion efficiency.

Quantum dots are nanoparticles that can be used to emit light, and by precisely controlling the size of the particle, the color of the light can be controlled. They’ve been used for some time but can be expensive and lack optimal color control. The manufacturing techniques being developed at OSU, which should be able to scale up to large volumes for low-cost commercial applications, will provide new ways to offer the precision needed for better color control.

By comparison, some past systems to create these nanoparticles for uses in optics, electronics or even biomedicine have been slow, expensive, sometimes toxic and often wasteful.

Oher applications of these systems are also possible. Cell phones and portable electronic devices might use less power and last much longer on a charge. “Taggants,” or compounds with specific infrared or visible light emissions, could be used for precise and instant identification, including control of counterfeit bills or products.

OSU is already working with the private sector to help develop some uses of this technology, and more may evolve. The research has been supported by Oregon BEST and the National Science Foundation Center for Sustainable Materials Chemistry.

 

Media Contact: 
Source: 

Greg Herman, 541-737-2496

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