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  • richardmitnick 11:22 am on November 21, 2019 Permalink | Reply
    Tags: "UW aerospace engineer part of $1.7M grant to study corals", , , , University of Washington   

    From University of Washington: “UW aerospace engineer part of $1.7M grant to study corals” 

    U Washington

    From University of Washington

    November 15, 2019

    1
    An interdisciplinary team of researchers from multiple institutions — including the University of Washington — has received a two-year $1.7 million National Science Foundation grant to study coral growth.Michael Webster

    Coral reefs are disappearing at a rapid rate around the world. They’re threatened by human impacts at both local and global scales, and they’re facing dire predictions for the future.

    But conservation and restoration efforts have been a challenge because corals — an animal host coexisting with algae, bacteria, viruses and fungi — act more like cities than individuals.

    Now an interdisciplinary team of researchers from multiple institutions, including the University of Washington, has received a two-year, $1.7 million National Science Foundation grant to study coral growth. The team includes Jinkyu Yang, a UW associate professor of aeronautics and astronautics.

    “This project is good example of how aerospace engineers, marine biologists, chemical engineers and computer scientists can work together,” Yang said. “Successful aerospace missions often rely on advanced materials, which can be used for other fields of studies. Likewise, materials — even living materials — in other fields can inspire the design of aerospace engineering materials.”

    The researchers will study corals as though they are tiny manufacturing sites in the ocean. The team will focus on three unique characteristics of coral communities: the corals’ calcium carbonate skeletons, which provide 3D structures to shelter diverse sea life; corals’ ability to self-heal damage to their tissues; and the corals’ symbiotic relationships with other organisms.

    At the UW, Yang’s group will 3D print scaffolds to guide coral growth and look into new techniques to measure how well the corals grow.

    Collaborating with Yang are Judith Klein-Seetharaman at the Colorado School of Mines, Hollie Putnam of the University of Rhode Island, Lenore Cowen at Tufts University and Nastassja Lewinski at Virginia Commonwealth University.

    “We are at a tipping point, where new research efforts could have a snowball effect in drastically increasing our understanding of corals,” said project lead Klein-Seetharaman, an associate professor of chemistry at Colorado School of Mines.

    For more information, contact Yang at jkyang@aa.washington.edu.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    u-washington-campus
    The University of Washington is one of the world’s preeminent public universities. Our impact on individuals, on our region, and on the world is profound — whether we are launching young people into a boundless future or confronting the grand challenges of our time through undaunted research and scholarship. Ranked number 10 in the world in Shanghai Jiao Tong University rankings and educating more than 54,000 students annually, our students and faculty work together to turn ideas into impact and in the process transform lives and our world. For more about our impact on the world, every day.
    So what defines us —the students, faculty and community members at the University of Washington? Above all, it’s our belief in possibility and our unshakable optimism. It’s a connection to others, both near and far. It’s a hunger that pushes us to tackle challenges and pursue progress. It’s the conviction that together we can create a world of good. Join us on the journey.

     
  • richardmitnick 2:15 pm on November 12, 2019 Permalink | Reply
    Tags: "Swordfish as oceanographers? Satellite tags allow research of ocean’s ‘twilight zone’ off Florida", , In January the researchers plan to tag more swordfish in the Red Sea off the coast of Saudi Arabia., , Researchers can re-create an individual fish’s precise travel path in three dimensions allowing for the first time scientists to understand where these animals feed., The initial phase of the Florida swordfish-tagging project was funded by the Woods Hole Oceanographic Institution., This is the first time satellite position tags have successfully been placed on swordfish caught off the coast of the United States., This work is providing new insight into deep-sea ecosystems., University of Washington, With the new Florida-based project the team hopes not only to learn more about swordfish but to further explore the mesopelagic or “twilight zone” of the Atlantic Ocean.   

    From University of Washington: “Swordfish as oceanographers? Satellite tags allow research of ocean’s ‘twilight zone’ off Florida” 

    U Washington

    From University of Washington

    November 4, 2019
    Hannah Hickey

    1
    Two tags were attached to this swordfish off the coast of Florida in August. A small antenna on the fin sends data when the fish breaks the surface. The black rubber bulb takes detailed measurements of water pressure and temperature. The two tags, made by Wildlife Computers, communicate with the scientists via satellite.Steve Dougherty

    Researchers from the University of Washington are using high-tech tags to record the movements of swordfish — big, deep-water, migratory, open-ocean fish that are poorly studied — and get a window into the ocean depths they inhabit.

    The researchers tagged five swordfish in late August off the coast of Miami: Max, Simone, Anthony, Rex and Oliver. Their movements can now be viewed in near-real time. And although swordfish are a prized catch, these ones aren’t at higher risk, researchers say, since the website updates only every few hours and these fast-swimming fish spend most of their time far from shore.

    “These are animals that migrate into the ocean’s twilight zone that we know next to nothing about,” said Peter Gaube, an oceanographer at the UW Applied Physics Laboratory. “Swordfish in different regions have very different behavior. We hope to learn more about these amazing animals and their environment as they migrate between regions.”

    This is the first time satellite position tags have successfully been placed on swordfish caught off the coast of the United States.

    Earlier tags on swordfish relied on measurements of temperature and light to approximate the animal’s position, which resulted in errors greater than 60 miles (100 km). The new tags act together as a pair: One records detailed temperature, light and depth measurements as the fish is swimming, while the other beams back the precise location when the fish surfaces each day.

    By comparing the saved observations with computer reconstructions of ocean conditions, the researchers can re-create an individual fish’s precise travel path in three dimensions, allowing for the first time scientists to understand where these animals feed and providing new insight into deep-sea ecosystems.

    2
    Peter Gaube (wearing purple gloves) and Camrin Braun (far right) attach a satellite tag on a swordfish in August 2019 off the coast of Florida.Steve Dougherty

    Gaube and collaborator Camrin Braun, a UW assistant professor of aquatic and fishery sciences, have placed similar satellite tags on other ocean predators, including great white sharks, blue sharks, whale sharks and manta rays.

    “Swordfish are different from the surface-oriented fish that have been tagged, like sharks or whales — these are deep-sea fish,” Braun said. “But because they migrate up and down every day, they break the surface, and the new types of tags allow incredibly fast communication.”

    Swordfish often jump at the surface, a behavior that helps make them a popular target for sport fishing.

    “That’s why we’re so excited,” Braun said. “Swordfish are a particularly good platform to help us make observations in the deep ocean, while at the same time giving us a better understanding of why and how this predator makes a living.”

    Recently, the UW researchers customized satellite tags made by Wildlife Computers of Redmond, Washington, to work on swordfish. These top predators swim long distances, commonly reach 10 feet (3 meters) in length, and are named for the long, flat bill they use to slash and injure prey.

    The fish can swim at 50 miles per hour and typically spend the day at a third of a mile (550 meters) deep. They rise to the surface at night, along with millions of other fish and squid, upon which the swordfish feed.

    A recent paper by Braun, Gaube and collaborators, published in June in the ICES Journal of Marine Science, analyzed 16 swordfish tagged with simpler tags in the western Atlantic, off Florida and the Grand Banks, and in the Northeast Atlantic, off the coast of Portugal. The results show that juvenile swordfish tagged off Portugal tended to stick to that area, while the mostly adult individuals tagged in the western Atlantic swam long distances between the Grand Banks off Newfoundland and the waters near Cuba.

    With the new Florida-based project the team hopes not only to learn more about swordfish but to further explore the mesopelagic, or “twilight zone” of the Atlantic Ocean. These partially lit waters from a tenth to half a mile (200 to 800 meters) in depth are hard to reach and poorly studied, even as fishing is beginning to target these environments.

    In January the researchers plan to tag more swordfish in the Red Sea, off the coast of Saudi Arabia.

    “This will provide the baseline data we need to understand this ecosystem before it is exploited any further,” Gaube said.

    The initial phase of the Florida swordfish-tagging project was funded by the Woods Hole Oceanographic Institution. Researchers are looking for support from community members, in the sport fishing community, environmental groups or others, to monitor other swordfish and gather more data.

    Next the team is designing new tags that can hold more sensors that could measure properties such as acceleration, depth, water temperature, muscle temperature and stomach temperature. The next-generation tags could also include cameras that could be set to trigger based on various behaviors, such as when the fish dives to a certain depth. They hope to eventually use results from the Florida tagging project to guide shipboard sampling of the marine environment alongside swordfish “oceanographers.”

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    u-washington-campus
    The University of Washington is one of the world’s preeminent public universities. Our impact on individuals, on our region, and on the world is profound — whether we are launching young people into a boundless future or confronting the grand challenges of our time through undaunted research and scholarship. Ranked number 10 in the world in Shanghai Jiao Tong University rankings and educating more than 54,000 students annually, our students and faculty work together to turn ideas into impact and in the process transform lives and our world. For more about our impact on the world, every day.
    So what defines us —the students, faculty and community members at the University of Washington? Above all, it’s our belief in possibility and our unshakable optimism. It’s a connection to others, both near and far. It’s a hunger that pushes us to tackle challenges and pursue progress. It’s the conviction that together we can create a world of good. Join us on the journey.

     
  • richardmitnick 9:58 am on November 6, 2019 Permalink | Reply
    Tags: "New technique lets researchers map strain in next-gen solar cells", A new type of electron backscatter diffraction, , , , , FOM Institute for Atomic and Molecular Physics in the Netherlands, Lead halide perovskites, , University of Washington   

    From University of Washington: “New technique lets researchers map strain in next-gen solar cells” 

    U Washington

    From University of Washington

    October 31, 2019
    James Urton

    1

    People can be good at hiding strain, and we’re not alone. Solar cells have the same talent. For a solar cell, physical strain within its microscopic crystalline structure can interrupt its core function — converting sunlight into electricity — by essentially “losing” energy as heat. For an emerging type of solar cell, known as lead halide perovskites, reducing and taming this loss is key to improving efficiency and putting the perovskites on par with today’s silicon solar cells.

    In order to understand where strain builds up within a solar cell and triggers the energy loss, scientists must visualize the underlying grain structure of perovskite crystals within the solar cell. But the best approach involves bombarding the solar cell with high-energy electrons, which essentially burns the solar cell and renders it useless.

    Researchers from the University of Washington and the FOM Institute for Atomic and Molecular Physics in the Netherlands have developed a way to illuminate strain in lead halide perovskite solar cells without harming them. Their approach, published online Sept. 10 in Joule, succeeded in imaging the grain structure of a perovskite solar cell, showing that misorientation between microscopic perovskite crystals is the primary contributor to the buildup of strain within the solar cell. Crystal misorientation creates small-scale defects in the grain structure, which interrupt the transport of electrons within the solar cell and lead to heat loss through a process known as non-radiative recombination.

    3
    Image of a perovskite solar cell, obtained by the team’s improved method for electron imaging, showing individual grain structure.Jariwala et al., Joule, 2019

    “By combining our optical imaging with the new electron detector developed at FOM, we can actually see how the individual crystals are oriented and put together within a perovskite solar cell,” said senior author David Ginger, a UW professor of chemistry and chief scientist at the UW-based Clean Energy Institute. “We can show that strain builds up due to the grain orientation, which is information researchers can use to improve perovskite synthesis and manufacturing processes to realize better solar cells with minimal strain — and therefore minimal heat loss due to non-radiative recombination.”

    Lead halide perovskites are cheap, printable crystalline compounds that show promise as low-cost, adaptable and efficient alternatives to the silicon or gallium arsenide solar cells that are widely used today. But even the best perovskite solar cells lose some electricity as heat at microscopic locations scattered across the cell, which dampens the efficiency.

    Scientists have long used fluorescence microscopy to identify the locations on perovskite solar cells’ surface that reduce efficiency. But to identify the locations of defects causing the heat loss, researchers need to image the true grain structure of the film, according to first author Sarthak Jariwala, a UW doctoral student in materials science and engineering and a Clean Energy Institute Graduate Fellow.

    “Historically, imaging the solar cell’s underlying true grain structure has not been possible to do without damaging the solar cell,” said Jariwala.

    Typical approaches to view the internal structure utilize a form of electron microscopy called electron backscatter diffraction, which would normally burn the solar cell. But scientists at the FOM Institute for Atomic and Molecular Physics, led by co-authors Erik Garnett and Bruno Ehrler, developed an improved detector that can capture electron backscatter diffraction images at lower exposure times, preserving the solar cell structure.

    The images of perovskite solar cells from Ginger’s lab reveal a grain structure that resembles a dry lakebed, with “cracks” representing the boundaries among thousands of individual perovskite grains. Using this imaging data, the researchers could for the first time map the 3D orientation of crystals within a functioning perovskite solar cell. They could also determine where misalignment among crystals created strain.

    4
    The thin lines show the grain structure of a perovskite solar cell obtained using a new type of electron backscatter diffraction. Researchers can use a different technique to map sites of high energy loss (dark purple) and low energy loss (yellow).Jariwala et al., Joule, 2019

    When the researchers overlaid images of the perovskite’s grain structure with centers of non-radiative recombination, which Jariwala imaged using fluorescence microscopy, they discovered that non-radiative recombination could also occur away from visible boundaries.

    “We think that strain locally deforms the perovskite structure and causes defects,” said Ginger. “These defects can then disrupt the transport of electrical current within the solar cell, causing non-radiative recombination — even elsewhere on the surface.”

    While Ginger’s team has previously developed methods to “heal” some of these defects that serve as centers of non-radiative recombination in perovskite solar cells, ideally researchers would like to develop perovskite synthesis methods that would reduce or eliminate non-radiative recombination altogether.

    “Now we can explore strategies like controlling grain size and orientation spread during the perovskite synthesis process,” said Ginger. “Those might be routes to reduce misorientation and strain — and prevent defects from forming in the first place.”

    Co-authors on the paper are Hongyu Sun, Gede Adhyaksa, Adries Lof and Loreta Muscarella with the FOM Institute for Atomic and Molecular Physics. The research was funded by the U.S. Department of Energy, U.S. National Science Foundation, the UW Clean Energy Institute, TKI Urban Energy, the European Research Council and the Dutch Science Foundation.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    u-washington-campus
    The University of Washington is one of the world’s preeminent public universities. Our impact on individuals, on our region, and on the world is profound — whether we are launching young people into a boundless future or confronting the grand challenges of our time through undaunted research and scholarship. Ranked number 10 in the world in Shanghai Jiao Tong University rankings and educating more than 54,000 students annually, our students and faculty work together to turn ideas into impact and in the process transform lives and our world. For more about our impact on the world, every day.
    So what defines us —the students, faculty and community members at the University of Washington? Above all, it’s our belief in possibility and our unshakable optimism. It’s a connection to others, both near and far. It’s a hunger that pushes us to tackle challenges and pursue progress. It’s the conviction that together we can create a world of good. Join us on the journey.

     
  • richardmitnick 11:21 am on November 1, 2019 Permalink | Reply
    Tags: , , , , , University of Washington, UW HuskySat-1 cubesat   

    From University of Washington: “Washington’s first student-built satellite preparing for launch” 

    U Washington

    From University of Washington

    October 31, 2019
    Hannah Hickey

    1
    Team members Paige Northway, Anika Hidayat, John Correy and Eli Reed (back row, left to right) watch in June as Henry Martin of Nanoracks does a “fit test” to ensure that the satellite fits inside the silver box. The digital clock on the wall counts down the days, minutes and seconds until launch.Dennis Wise/University of Washington

    A University of Washington satellite smaller than a loaf of bread will, if all goes well, launch this weekend on its way to low-Earth orbit. It will be the first student-built satellite from Washington state to go into space.

    HuskySat-1 is one of seven student-built satellites from around the country scheduled to launch at 9:30 a.m. Eastern time Saturday, Nov. 2, from NASA’s Wallops Flight Facility on the Virginia coast.

    3

    PURPOSE

    HuskySat-1 is a 3U CubeSat designed, built, and tested by the Husky Satellite Lab. HuskySat-1’s goal is to test two experimental payloads, a Pulsed Plasma Thruster, and a high-frequency K-band communication system, as well as hosting an Amateur Radio Linear Transponder.

    HuskySat-1 is being developed by an interdisciplinary team at the University of Washington and will be launched into Low Earth Orbit to become the first amateur satellite from Washington state. This CubeSat will demonstrate the capabilities of new technologies being developed at the University of Washington and expand the capabilities of CubeSats as a whole. In particular, a high-thrust pulsed plasma thruster (PPT), and high-gain communications system will form the core technology suite on board the satellite. The HuskySat-1 will also be flying a newly developed Amateur Radio Linear Transponder developed by AMSAT which will contribute to the worldwide communication networks built and operated by ham radio enthusiasts.

    2
    HuskySat-1 sits under protection in the UW satellite lab in June, as it prepared to leave on its journey to Virginia and then to low-Earth orbit.Dennis Wise/University of Washington

    “It will be exciting once it’s in orbit,” said Paige Northway, a UW doctoral student in Earth and Space Sciences who has been involved since the project’s inception. “To me, the completion will be when we can get data from the satellite and send instructions back.”

    HuskySat-1’s last moments on Earth will be broadcast live on NASA TV. The satellites are hitching a ride on the Cygnus cargo spacecraft, whose first stop will be the International Space Station to resupply astronauts and swap out materials. In early 2020 the spacecraft will leave the station and fly up to an altitude of about 310 miles (500 kilometers), where a NASA engineer will eject the student-build satellites.

    4
    An earlier model of the satellite, shown here in the lab, had solar panels on wings that unfold. The final model has solar panels attached on three sides to provide electrical power.Dennis Wise/University of Washington

    The UW creation is a type of CubeSat, a small satellite that measures exactly 10 centimeters (about 3 inches) along each side. HuskySat-1 is a “three-unit” system, meaning it’s the shape of a stack of three CubeSat-sized blocks. These miniature satellites were first created as a way for engineering students to test software with smaller, cheaper devices they could build from start to finish in a few years. But the devices are growing in popularity, with Planet and other companies now using nanosatellites for commercial ventures.

    NASA’s CubeSat Launch Initiative helps students and nonprofit groups launch these instrument systems into space. The Washington State University satellite, CougSat-1, is scheduled to launch in October 2020.

    The UW satellite weighs just under 7 pounds (3.14 kilograms) and took five years to design and build. Undergraduate and graduate students from aeronautics and astronautics, mechanical engineering, computer engineering, Earth and space sciences, physics and other departments spent hundreds of hours building the system in the Husky Satellite Lab.

    Its trip into low-Earth orbit is organized by Nanoracks, a Texas company that, like Spaceflight Industries of Seattle and other businesses, coordinates smaller groups to provide access to launch vehicles.

    After extensive testing and final checkouts this summer, Northway hand-delivered the satellite in September to the Nanoracks facility in Houston, where it was placed into the box that will carry it to space.

    “These students have gained firsthand experience on what is required to build and launch a satellite, and aerospace companies have already snapped up many of them,” said Robert Winglee, a professor of Earth and space sciences and the team’s faculty adviser as director of the UW Advanced Propulsion Lab. “Meanwhile, the UW is making its first steps to a continuing hardware presence in space. What more could you wish for?”

    Three antennas installed on the roof of Johnson Hall will allow students to get information like position and altitude and send instructions to the satellite as it passes overhead. A camera built in collaboration with students at Raisbeck Aviation High School in Tukwila, Washington, will send back grainy, black-and-white photos of Earth. Students will also be able to control the satellite’s camera and thruster remotely.

    “A lot of information is taught in classes, but only in a hands-on environment can you experience things like design, integration of subsystems, project management and documentation,” said team member Anika Hidayat, a senior in mechanical engineering.

    HuskySat-1 will orbit at an angle of 51.6 degrees, traveling between 51.6 degrees north and south, at an altitude of 310 miles (500 kilometers) and at more than 4 miles (7 kilometers) per second. Once the students locate their satellite they will be able to predict its travel path.

    5
    White lines show the satellite’s projected travel path, orbiting at an angle of 51.6 degrees from the equator. The antennas at the UW will be able to communicate with HuskySat-1 when it flies inside the red circle.Paige Northway/University of Washington

    Some of the student-built parts will still be in test mode. A custom-built thruster uses sparks to vaporize small amounts of solid sulfur as a propellant. The thruster will fire about 100 times as the satellite passes over Seattle, only enough thrust to provide a slight nudge. A high-bandwidth communications system built by former graduate student Paul Sturmer, now at Blue Origin, transmits at 24 Gigahertz, allowing the satellite to quickly send reams of data. That system will send down a test packet from space.

    “Usually people buy most of the satellite and build one part of it. We built all the parts,” Northway said. “It was a pretty serious undertaking.”

    The UW group will control HuskySat-1 for three months. In the spring it will transfer ownership and responsibility to AMSAT, the Radio Amateur Satellite Corporation, which provided the main communication system. The satellite will begin to lose altitude in about three years and will burn up as it re-enters Earth’s atmosphere. (NASA requires that all such objects deorbit within 25 years.)

    HuskySat-1 grew out of a special topics course in the UW Department of Earth & Space Sciences. In 2016 members formed a registered student organization, the Husky Satellite Lab at UW.

    “Being involved with this has taught me a lot,” said current team captain John Correy, a UW graduate student in aeronautics and astronautics. “But beyond that, it’s just validation that I’m in the right industry.”

    As the Husky Satellite Lab wraps up this half-decade-long effort it plans to next tackle a NanoLab project — a partly prebuilt system that can be adapted to conduct experiments in microgravity — for travel aboard a Blue Origin vehicle. Students plan to complete that project by spring of 2020.

    HuskySat-1 was supported by a NASA Undergraduate Student Instrument Project award, which funded the satellite’s development and launch with a private space contractor. The team also was supported by NASA, the Washington NASA Space Grant Consortium, the UW and several companies that provided equipment for the satellite and antenna.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    u-washington-campus
    The University of Washington is one of the world’s preeminent public universities. Our impact on individuals, on our region, and on the world is profound — whether we are launching young people into a boundless future or confronting the grand challenges of our time through undaunted research and scholarship. Ranked number 10 in the world in Shanghai Jiao Tong University rankings and educating more than 54,000 students annually, our students and faculty work together to turn ideas into impact and in the process transform lives and our world. For more about our impact on the world, every day.
    So what defines us —the students, faculty and community members at the University of Washington? Above all, it’s our belief in possibility and our unshakable optimism. It’s a connection to others, both near and far. It’s a hunger that pushes us to tackle challenges and pursue progress. It’s the conviction that together we can create a world of good. Join us on the journey.

     
  • richardmitnick 2:13 pm on October 31, 2019 Permalink | Reply
    Tags: "Precision mapping with satellite and drone photos could help predict infections of a widespread tropical disease", A team led by the University of Washington and Stanford University has discovered clues in the environment that help identify transmission hotspots for schistosomiasis., More than 200 million people have schistosomiasis which is treatable but has been difficult to eliminate from some regions of the world., , , The disease is found across sub-Saharan Africa as well as in South America; the Caribbean; the Middle East; and East and Southeast Asia., University of Washington   

    From University of Washington and Stanford University: “Precision mapping with satellite, drone photos could help predict infections of a widespread tropical disease” 

    Stanford University Name
    Stanford University

    U Washington

    From University of Washington

    October 28, 2019
    Michelle Ma

    1
    A drone image showing a village in northwestern Senegal and agricultural land, separated by a river with lush vegetation. Researchers use rigorous field sampling and aerial images to precisely map communities that are at greatest risk for schistosomiasis infection. Andrew Chamberlin/Stanford University.

    Satellite images, drone photos and even Google Earth could help identify communities most at risk for getting one of the world’s worst tropical diseases.

    A team led by the University of Washington and Stanford University has discovered clues in the environment that help identify transmission hotspots for schistosomiasis, a parasitic disease that is second only to malaria in its global health impact. The research, published Oct. 28 in the Proceedings of the National Academy of Sciences, uses rigorous field sampling and aerial images to precisely map communities that are at greatest risk for schistosomiasis.

    “This is a game-changer for developing-country public health agencies, because it will make it possible for them to efficiently find the villages that need their help the most,” said lead author Chelsea Wood, an assistant professor in the UW School of Aquatic and Fishery Sciences.

    More than 200 million people have schistosomiasis, which is treatable but has been difficult to eliminate from some regions of the world. Schistosomes, the worms that cause this disease, grow within freshwater snails, where they multiply and are released into the waters of rivers, lakes and streams. The worms infect people by penetrating their skin when they swim, bathe or wade. Schistosomiasis causes bloody urine and stool and abdominal pain, and can damage the liver, spleen, intestines, lungs and bladder. In children, the infection can stunt growth and impair cognitive development.

    2
    Children washing sheep in Penene, Senegal, May 2015.Chelsea Wood/University of Washington.

    The disease is found across sub-Saharan Africa, as well as in South America, the Caribbean, the Middle East, and East and Southeast Asia. Though schistosomiasis is treatable with the drug praziquantel, it’s easy for a person to become re-infected after treatment if they swim or bathe in freshwater where the parasite is present.

    The World Health Organization recently recognized that efforts to slow transmission of the disease through drug distribution weren’t working in some regions. In addition to drug distribution, WHO now recommends targeting the types of snails that transmit the parasitic worms, which is how this research team got involved.

    “The ecological side of the problem is what’s holding us back from schistosomiasis control and elimination — and now ecologists are stepping in and filling that gap,” Wood said. “It’s an exciting time because there’s so much for us to learn. The kind of innovation we have introduced is just the beginning of what ecologists have to contribute to the control of schistosomiasis.”

    3
    Researchers process the vegetation from a sampling point in northwestern Senegal, May 2016.Chelsea Wood/University of Washington.

    The researchers worked across more than 30 sites in northwestern Senegal, where villages use a local river and lake for everything from bathing and swimming to washing dishes and clothes. This location was the epicenter of the largest schistosomiasis outbreak ever recorded, in the mid-1980s.

    The researchers first set out to methodically count and map the distribution of snails across each site over two years. The fieldwork was difficult and exhausting — they couldn’t let the schistosome-infested water touch their skin while they waded chest-deep to sample mud and plants. It was hot and humid, and the thick shoreline vegetation was full of mosquitoes, spiders, snakes — and even feral dogs.

    4
    Co-author Andrew Chamberlin performs deep-water floating vegetation sampling at Mbarigot, Senegal, May 2017.Chelsea Wood/University of Washington.

    Their fieldwork demonstrated that snails were found in the river in patchy and inconsistent distributions over time. Snails might be present in one location, then completely absent three months later. Given the snails’ ephemeral nature, the researchers realized that targeting aggregations of snails for removal might not be an efficient way to reduce schistosomiasis transmission.

    Instead, they shifted their focus to the habitat where snails live. The snails thrive in unrooted, floating vegetation that is visible in images from satellites and drones.

    Considering these habitat features, plus other data they had gathered about each site such as snail density, village size and location, they used models to evaluate which factors could best predict schistosomiasis transmission. The total area of a water access point and the area of floating vegetation were the two best indicators that human infection would occur nearby.

    These habitat features are all easy to measure in drone or satellite imagery.

    4
    Freshwater snails that transmit schistosomiasis thrive in unrooted, floating vegetation that can be seen in aerial images. In this photo, the dark, patchy vegetation in the water is the ideal habitat for snails.Andrew Chamberlin/Stanford University.

    “Counting snails is not an easy undertaking, and it also produces data that are not as useful as the data you can get from a drone,” Wood said. “Once we understand the association between snail presence and particular habitat features, we can use drone and satellite imagery to detect those habitat features. This cuts the time needed to evaluate the risk of schistosomiasis infection down to a fraction of what it would be if you were just looking at snails.”

    Public health agencies in Senegal can now look at aerial images across their jurisdiction, find areas with the most floating vegetation in water access points and target those villages for schistosomiasis treatment, the researchers explained.

    5
    There are many uses for the water access point at Ndiawdoune, Senegal, including dishwashing, bathing, fishing and water for livestock.Chelsea Wood/University of Washington

    “Now we can take these aerial images season to season and have an idea of how the pathogenic landscape changes in time and space. This can give us a better idea of infection rates,” said co-author Giulio De Leo, a biology professor at Stanford University. “This project has been a tremendous effort and an example of collaborative research that would be impossible by a single person or a single lab.”

    The team is also trying to use machine learning to automate the identification of floating vegetation in photos, making it even easier for agencies to use the information. They plan to test their approach in other parts of Africa at a broader scale, using publicly available infection data and satellite imagery.

    “We’re cautiously optimistic, but we still have some work to do to generalize our findings to new contexts,” said co-author Susanne Sokolow, a research scientist at Stanford University. “If, indeed, we find that the predictors for schistosomiasis are scalable and automatable, then we will have a powerful new tool in the fight against the disease, and one that fills a critical capacity gap: a way to efficiently target environmental interventions alongside human treatment to combat the disease.”

    Other co-authors are Isabel Jones, Andrew Chamberlin and Andrea Lund of Stanford University; Kevin Lafferty of U.S. Geological Survey at University of California, Santa Barbara; Armand Kuris of University of California, Santa Barbara; Merlijn Jocque of Royal Belgian Institute of Natural Sciences; Skylar Hopkins of Virginia Tech; Evan Fiorenza and Grant Adams of the University of Washington; Julia Buck of University of North Carolina Wilmington; Ana Garcia-Vedrenne of University of California, Los Angeles; Jason Rohr of University of Notre Dame; Fiona Allan, Bonnie Webster and Muriel Rabone of London’s Natural History Museum; Joanne Webster of Royal Veterinary College, University of London; and Lydie Bandagny, Raphaël Ndione, Simon Senghor, Anne-Marie Schacht, Nicolas Jouanard and Gilles Riveau of Biomedical Research Center EPLS in Saint Louis, Senegal.

    This research was funded by University of Michigan, the Alfred P. Sloan Foundation, the Wellcome Trust, the Bill and Melinda Gates Foundation, Stanford University, the National Institutes of Health and the National Science Foundation.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Stanford University

    Leland and Jane Stanford founded the University to “promote the public welfare by exercising an influence on behalf of humanity and civilization.” Stanford opened its doors in 1891, and more than a century later, it remains dedicated to finding solutions to the great challenges of the day and to preparing our students for leadership in today’s complex world. Stanford, is an American private research university located in Stanford, California on an 8,180-acre (3,310 ha) campus near Palo Alto. Since 1952, more than 54 Stanford faculty, staff, and alumni have won the Nobel Prize, including 19 current faculty members

    Stanford University Seal

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    The University of Washington is one of the world’s preeminent public universities. Our impact on individuals, on our region, and on the world is profound — whether we are launching young people into a boundless future or confronting the grand challenges of our time through undaunted research and scholarship. Ranked number 10 in the world in Shanghai Jiao Tong University rankings and educating more than 54,000 students annually, our students and faculty work together to turn ideas into impact and in the process transform lives and our world. For more about our impact on the world, every day.
    So what defines us —the students, faculty and community members at the University of Washington? Above all, it’s our belief in possibility and our unshakable optimism. It’s a connection to others, both near and far. It’s a hunger that pushes us to tackle challenges and pursue progress. It’s the conviction that together we can create a world of good. Join us on the journey.

     
  • richardmitnick 7:37 am on October 30, 2019 Permalink | Reply
    Tags: "NSF invests in cyberinfrastructure institute to harness cosmic data", Cyberinfrastructure, , SCIMMA-Scalable Cyberinfrastructure Institute for Multi-Messenger Astrophysics, University of Washington,   

    From University of Washington: “NSF invests in cyberinfrastructure institute to harness cosmic data” 

    U Washington

    From University of Washington

    The National Science Foundation awarded the University of Wisconsin-Milwaukee and nine collaborating organizations, including the University of Washington, $2.8 million for a two-year “conceptualization phase” of the Scalable Cyberinfrastructure Institute for Multi-Messenger Astrophysics.

    1
    The night sky at Palouse Falls in southeastern Washington.Mark Stone/University of Washington

    SCIMMA’s goal is to develop algorithms, databases and computing and networking cyberinfrastructure to help scientists interpret multi-messenger observations. Multi-messenger astrophysics combines observations of light, gravitational waves and particles to understand some of the most extreme events in the universe. For example, the observation of both gravitational waves and light from the collision of two neutron stars in 2017 helped explain the origin of heavy elements, allowed an independent measurement of the expansion of the universe and confirmed the association between neutron-star mergers and gamma-ray bursts.

    The institute would facilitate global collaborations, thus transcending the capabilities of any single existing institution or team. It is directed by Patrick Brady, a professor of physics at the University of Wisconsin-Milwaukee and director of the Center for Gravitation, Cosmology and Astrophysics. One of three co-principal investigators on the project is Mario Jurić, a UW associate professor of astronomy and senior data science fellow at the UW eScience Institute.

    As part of SCIMMA, UW researchers will work to develop a “transient alert” system that will alert researchers around the world about cosmic events picked up, for example, by astronomical observatories.

    “These events could include phenomena like collisions between black holes and neutron stars detected via gravitational waves, exploding supernovae detected by neutrino emissions, and other energetic phenomena detected in visible wavelengths of light,” said Jurić, who is also a faculty member with the UW DIRAC Institute. “UW researchers have demonstrated these technologies as part of the Zwicky Transient Facility project, where the UW-built ZTF Alert Distribution System transmitted more than 100 million alerts over the past two years.”

    Zwicky Transient Facility (ZTF) instrument installed on the 1.2m diameter Samuel Oschin Telescope at Palomar Observatory in California. Courtesy Caltech Optical Observatories

    Caltech Palomar Samuel Oschin 48 inch Telescope, located in San Diego County, California, United States, altitude 1,712 m (5,617 ft)

    W researchers will also help develop a prototype remote analysis platform, which will allow scientists to analyze archived multi-messenger astrophysics using future resources provided by SCIMMA, said Jurić.

    SCIMMA’s two-year conceptualization phase began Sept. 1. Among its goals are enabling seamless co-analysis of disparate datasets by supporting the interoperability of software and data services. In addition, over the next two years SCIMMA will develop education and training curricula designed to enhance the STEM workforce, according to an announcement by the NSF.

    “Multi-messenger astrophysics is a data-intensive science in its infancy that is already transforming our understanding of the universe,” said Brady. “The promise of multi-messenger astrophysics, however, can be realized only if sufficient cyberinfrastructure is available to rapidly handle, combine and analyze the very large-scale distributed data from all types of astronomical measurements. The conceptualization phase of SCIMMA will balance rapid prototyping, novel algorithm development and software sustainability to accelerate scientific discovery over the next decade and more.”

    Additional project collaborators include Columbia University; the Center for Advanced Computing and Department of Astronomy at Cornell University; Las Cumbres Observatory, a California-based network of observatories; Michigan State University; Pennsylvania State University; the University of California, Santa Barbara; the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign; and the Texas Advanced Computing Center at the University of Texas at Austin.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    u-washington-campus
    The University of Washington is one of the world’s preeminent public universities. Our impact on individuals, on our region, and on the world is profound — whether we are launching young people into a boundless future or confronting the grand challenges of our time through undaunted research and scholarship. Ranked number 10 in the world in Shanghai Jiao Tong University rankings and educating more than 54,000 students annually, our students and faculty work together to turn ideas into impact and in the process transform lives and our world. For more about our impact on the world, every day.
    So what defines us —the students, faculty and community members at the University of Washington? Above all, it’s our belief in possibility and our unshakable optimism. It’s a connection to others, both near and far. It’s a hunger that pushes us to tackle challenges and pursue progress. It’s the conviction that together we can create a world of good. Join us on the journey.

     
  • richardmitnick 11:15 am on October 29, 2019 Permalink | Reply
    Tags: "UW team sending autonomous surfboard to explore Antarctic waters", , , In February the cybernetic surfboard plans to head north into Drake Passage, Investigating the summer conditions near Palmer Station on the Antarctic Peninsula, , The Wave Glider surfboard, University of Washington   

    From University of Washington: “UW team sending autonomous surfboard to explore Antarctic waters” 

    U Washington

    From University of Washington

    October 23, 2019
    Hannah Hickey

    1
    The Wave Glider is being lowered into the water in the Beaufort Sea in September 2018. The black solar panels provide electrical power, the white bulb provides satellite communication and the orange paddles drop down to give a forward push in wavy seas.San Nguyen

    This week, a surfboard arrived in Antarctica. Not only was it missing a surfer, but the unique board was covered in parts that let it move independently and measure the surrounding seawater.

    The University of Washington project will first use the Wave Glider to investigate the summer conditions near Palmer Station on the Antarctic Peninsula, to better understand how the warming ocean interacts with ice shelves that protrude from the shore.

    Then in February, the cybernetic surfboard plans to head north into Drake Passage, braving some of the stormiest seas on the planet that even large research ships try to avoid. The device uses wave power to propel itself, so the monster waves common in the Antarctic Circumpolar Current can help it move forward.

    “We hope to learn more about the connections between the ocean, atmosphere and sea ice in this dynamic environment,” said principal investigator Jim Thomson, an oceanographer at the UW Applied Physics Laboratory and professor of civil and environmental engineering.

    As it surfs along, the board will measure turbulence in the upper part of the Southern Ocean, which helps to measure how heat and other properties move between the water and the air. The board sends information back via satellite, and researchers will retrieve it once the mission is complete.

    The UW team’s previous project in late 2016 sent the same autonomous platform across the 500-mile channel between Antarctica and Argentina, with resulting papers in Oceanography magazine and the Journal of Atmospheric and Oceanic Technology. This time the board has more capabilities, including a winch that can lower an instrument to measure water temperature, salinity and pressure — key oceanographic observations — down to a depth of 150 meters (about 160 yards).

    3
    The robot surfboard will explore near Palmer Station, a U.S. research station on the Antarctic Peninsula. It will also measure conditions in Drake Passage, the stormy channel between Antarctica and South America.University of Washington.

    The revamped system also uses sonar to measure turbulence in the ocean and in the atmosphere, as well as a motion sensor to measure the waves. These measurements quantify the strength of the mixing occurring in the notoriously stormy region.

    The board is a modified version of a Wave Glider made by Liquid Robotics, a California-based subsidiary of Boeing Co.

    “The ability to collect vertical profile data with the new winch is a game changer. It makes the platform complete as an autonomous research tool,” said James Girton, an oceanographer at the Applied Physics Laboratory and affiliate assistant professor of oceanography.

    Girton and Ryan Newell, an oceanographer at the Applied Physics Laboratory, are putting the instrument out in the water this week from the icebreaker research vessel Laurence M. Gould. An outreach team is providing live interaction from the ship through Nov. 2.

    The coastal monitoring is part of the Long-Term Ecological Research Network at Palmer Station, a U.S. research station on an island off the Antarctic Peninsula. The research is funded by the National Science Foundation.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    u-washington-campus
    The University of Washington is one of the world’s preeminent public universities. Our impact on individuals, on our region, and on the world is profound — whether we are launching young people into a boundless future or confronting the grand challenges of our time through undaunted research and scholarship. Ranked number 10 in the world in Shanghai Jiao Tong University rankings and educating more than 54,000 students annually, our students and faculty work together to turn ideas into impact and in the process transform lives and our world. For more about our impact on the world, every day.
    So what defines us —the students, faculty and community members at the University of Washington? Above all, it’s our belief in possibility and our unshakable optimism. It’s a connection to others, both near and far. It’s a hunger that pushes us to tackle challenges and pursue progress. It’s the conviction that together we can create a world of good. Join us on the journey.

     
  • richardmitnick 10:14 am on October 23, 2019 Permalink | Reply
    Tags: "Humpback whale population on the rise after near miss with extinction", , , University of Washington   

    From University of Washington: “Humpback whale population on the rise after near miss with extinction” 

    U Washington

    From University of Washington

    October 21, 2019
    Dan DiNicola, School of Aquatic and Fishery Sciences

    1
    A population of humpback whales in the South Atlantic has rebounded from near extinction, a new study shows.iStock.com/Martin Hristov

    A population of humpback whales in the South Atlantic has rebounded from the brink of extinction.

    Intense pressure from the whaling industry in the 20th century saw the western South Atlantic population of humpbacks diminish to only 450 whales. It is estimated that 25,000 whales were caught over approximately 12 years in the early 1900s.

    Protections were put in place in the 1960s as scientists noticed worldwide that populations were declining. In the mid-1980s, the International Whaling Commission issued a moratorium on all commercial whaling, offering further safeguards for the struggling population.

    A new study co-authored by Grant Adams, John Best and André Punt from the University of Washington’s School of Aquatic and Fishery Sciences shows the western South Atlantic humpback (Megaptera novaeangliae) population has grown to 25,000. Researchers believe this new estimate is now close to pre-whaling numbers.

    The findings were published Oct. 16 in the journal Royal Society Open Science.

    “We were surprised to learn that the population was recovering more quickly than past studies had suggested,” said Best, a UW doctoral student.

    2
    A western South Atlantic humpback mother with her calf.L. Candisani/Courtesy Insituto Aqualie

    The study follows a previous assessment conducted by the International Whaling Commission between 2006 and 2015. Those findings indicated the population had only recovered to about 30% of its pre-exploitation numbers. Since that assessment was completed, new data has come to light, providing more accurate information on catches — including struck-and-lost rates — and genetics and life-history.

    “Accounting for pre-modern whaling and struck-and-lost rates where whales were shot or harpooned but escaped and later died, made us realize the population was more productive than we previously believed,” said Adams, a UW doctoral student who helped construct the new model.

    By incorporating detailed records from the whaling industry at the outset of commercial exploitation, researchers have a good idea of the size of the original population. Current population estimates are made from a combination of air- and ship-based surveys, along with advanced modeling techniques.

    The model built for this study provides scientists with a more comprehensive look at the recovery and current status of the humpback population. The authors anticipate it can be used to determine population recovery in other species in more detail as well.

    “We believe that transparency in science is important,” said Adams. “The software we wrote for this project is available to the public and anyone can reproduce our findings.”

    Lead author Alex Zerbini of the NOAA Alaska Fisheries Science Center’s Marine Mammal Laboratory stressed the importance of incorporating complete and accurate information when conducting these assessments, and providing population assessments without biases. These findings come as good news, he said, providing an example of how an endangered species can come back from near extinction.

    “Wildlife populations can recover from exploitation if proper management is applied,” Zerbini said.

    The study also looks at how the revival of South Atlantic humpbacks may have ecosystem-wide impacts. Whales compete with other predators, like penguins and seals, for krill as their primary food source. Krill populations may further be impacted by warming waters due to climate change, compressing their range closer to the poles.

    “Long-term monitoring of populations is needed to understand how environmental changes affect animal populations,” said Zerbini.

    Other co-authors are Phillip Clapham of Alaska Fisheries Science Center and Jennifer Jackson of the British Antarctic Survey.

    This research was funded by the Pew Bertarelli Ocean Legacy Project, the U.S. National Marine Fisheries Service-National Oceanic and Atmospheric Administration, the British Antarctic Survey and the University of Washington.

    For more information, contact Zerbini at alex.zerbini@noaa.gov, Best at jkbest@uw.edu and Adams at adamsgd@uw.edu.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    u-washington-campus
    The University of Washington is one of the world’s preeminent public universities. Our impact on individuals, on our region, and on the world is profound — whether we are launching young people into a boundless future or confronting the grand challenges of our time through undaunted research and scholarship. Ranked number 10 in the world in Shanghai Jiao Tong University rankings and educating more than 54,000 students annually, our students and faculty work together to turn ideas into impact and in the process transform lives and our world. For more about our impact on the world, every day.
    So what defines us —the students, faculty and community members at the University of Washington? Above all, it’s our belief in possibility and our unshakable optimism. It’s a connection to others, both near and far. It’s a hunger that pushes us to tackle challenges and pursue progress. It’s the conviction that together we can create a world of good. Join us on the journey.

     
  • richardmitnick 8:23 am on October 14, 2019 Permalink | Reply
    Tags: "Machine learning helps UW meet “always-on” wireless connectivity", , , Problems with wireless connectivity, University of Washington   

    From University of Washington: “Machine learning helps UW meet “always-on” wireless connectivity” 

    U Washington

    From University of Washington

    September 26, 2019
    Ignacio Lobos

    1

    When a biology lecturer noticed Poll Everywhere, a classroom response app, was failing to accept some of his students’ answers, he knew he had a serious problem.

    To find out what was happening, he sought help from UW-IT and Academic Technologies. They leveraged machine learning, analytics and data-driven insights to pinpoint an issue with the wireless connectivity and fix the problem.

    For David Morton, director of UW-IT’s Network & Telecommunications Design, this particular glitch represented something larger: “Our students have much higher expectations of technology: it just needs to work all the time.”

    After all, their grades can depend on “always-on network connectivity,” he explained.

    However, it is not just students who need secure and dependable wireless networks. Faculty and staff are increasingly relying on complex applications and smart devices.

    “Maintaining reliable communications is critical to everything we’re doing,” Morton said. “So, we’re leveraging machine learning to improve our systems, and in turn improving the classroom experience for students and faculty.”

    Artificial intelligence keeps Wi-Fi humming along

    Morton’s team uses Aruba NetInsight, a cloud-based system that employs artificial intelligence, to help track the health of the UW wireless network. The system analyzes the entire network, identifies performance problems in real time, and offers recommendations on how to fix them. As it tracks performance at the UW — and at 11 other major universities that also use the application — it learns as it amasses useful data that helps all institutions with critical decisions, such as where to expand Wi-Fi.

    The glitch in the biology lecturer’s classroom was indeed complex — when a wireless connection went down, it automatically switched some students to another connection, leaving their wireless devices in limbo as the switch took place, and their answers unrecorded.

    “It would have taken us countless hours of engineering sleuthing to track the problem and create a solution to prevent it from happening again,” Morton said. “But with machine learning, we zeroed in on the issues much faster.”

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    u-washington-campus
    The University of Washington is one of the world’s preeminent public universities. Our impact on individuals, on our region, and on the world is profound — whether we are launching young people into a boundless future or confronting the grand challenges of our time through undaunted research and scholarship. Ranked number 10 in the world in Shanghai Jiao Tong University rankings and educating more than 54,000 students annually, our students and faculty work together to turn ideas into impact and in the process transform lives and our world. For more about our impact on the world, every day.
    So what defines us —the students, faculty and community members at the University of Washington? Above all, it’s our belief in possibility and our unshakable optimism. It’s a connection to others, both near and far. It’s a hunger that pushes us to tackle challenges and pursue progress. It’s the conviction that together we can create a world of good. Join us on the journey.

     
  • richardmitnick 8:15 am on October 8, 2019 Permalink | Reply
    Tags: , University of Washington   

    From University of Washington: “New metasurface design can control optical fields in three dimensions” 

    U Washington

    From University of Washington

    October 4, 2019
    James Urton

    A team led by scientists at the University of Washington has designed and tested a 3D-printed metamaterial that can manipulate light with nanoscale precision. As they report in a paper published Oct. 4 in the journal Science Advances, their designed optical element focuses light to discrete points in a 3D helical pattern.

    The team’s design principles and experimental findings demonstrate that it is possible to model and construct metamaterial devices that can precisely manipulate optical fields with high spatial resolution in three dimensions. Though the team chose a helical pattern — a spiral helix — for their optical element to focus light, their approach could be used to design optical elements that control and focus light in other patterns.

    Devices with this level of precision control over light could be used not only to miniaturize today’s optical elements, such as lenses or retroreflectors, but also to realize new varieties. In addition, designing optical fields in three dimensions could enable creation of ultra-compact depth sensors for autonomous transportation, as well as optical elements for displays and sensors in virtual- or augmented-reality headsets.

    1
    A scanning electron micrograph image of the surface of the optical element.James Whitehead/University of Washington

    “This reported device really has no classical analog in refractive optics — the optics that we encounter in our day-to-day life,” said corresponding author Arka Majumdar, a UW assistant professor of electrical and computer engineering and physics, and faculty member at the UW Institute for Nano-Engineered Systems and the Institute for Molecular & Engineering Sciences. “No one has really made a device like this before with this set of capabilities.”

    The team, which includes researchers at the Air Force Research Laboratory and the University of Dayton Research Institute, took a lesser-used approach in the optical metamaterials field to design the optical element: inverse design. Using inverse design, they started with the type of optical field profile they wanted to generate — eight focused points of light in a helical pattern — and designed a metamaterial surface that would create that pattern.

    “We do not always intuitively know the appropriate structure of an optical element given a specific functionality,” said Majumdar. “This is where the inverse design comes in: You let the algorithm design the optics.”

    While this approach seems straightforward and avoids the drawbacks of trial-and-error design methods, inverse design isn’t widely used for optically active large-area metamaterials because it requires a large number of simulations, making inverse design computationally intensive.

    Here, the team avoided this pitfall thanks to an insight by Alan Zhan, lead author on the paper, who recently graduated the UW with a doctoral degree in physics. Zhan realized that the team could use Mie scattering theory to design the optical element. Mie scattering describes how light waves of a particular wavelength are scattered by spheres or cylinders that are similar in size to the optical wavelength. Mie scattering theory explains how metallic nanoparticles in stained glass can give certain church windows their bold colors, and how other stained glass artifacts change color in different wavelengths of light, according to Zhan.

    “Our implementation of Mie scattering theory is specific to certain shapes — spheres— which meant we had to incorporate those shapes into the design of the optical element,” said Zhan. “But, relying on Mie scattering theory significantly simplified the design and simulation process because we could make very specific, very precise calculations about the properties of light when it interacts with the optical element.”

    Their approach could be employed to include different geometries such as cylinders and ellipsoids.

    2
    These images show the performance of the 1,550-nanometer optical element. The images are light-intensity profiles of the optical field as it appears approximately 185 micrometers above the surface of the optical element. To the left is a simulated light-intensity profile that predicts how the optical element should perform. Note the focal point of light near the center of the image. To the right, an actual light-intensity profile of the optical element, showing that the device does produce a focal point of light at the predicted location. The researchers designed the element to focus light at eight such points at different distances above the element’s surface. Scale bar is 10 micrometers.Alan Zhan/University of Washington.

    The optical element the team designed is essentially a surface covered in thousands of tiny spheres of different sizes, arranged in a periodic square lattice. Using spheres simplified the design, and the team used a commercially available 3D printer to fabricate two prototype optical elements — the larger of the two with sides just 0.02 centimeters long — at the Washington Nanofabrication Facility on the UW campus. The optical elements were 3D-printed out of an ultraviolet epoxy on glass surfaces. One element was designed to focus light at 1,550 nanometers, the other at 3,000 nanometers.

    The researchers visualized the optical elements under a microscope to see how well they performed as designed — focusing light of either 1,550 or 3,000 nanometers at eight specific points along a 3D helical pattern. Under the microscope, most focused points of light were at the positions predicted by the team’s theoretical simulations. For example, for the 1,550-nanometer wavelength device, six of eight focal points were in the predicted position. The remaining two showed only minor deviations.

    With the high performance of their prototypes, the team would like to improve the design process to reduce background levels of light and improve the accuracy of the placement of the focal points, and to incorporate other design elements compatible with Mie scattering theory.

    “Now that we’ve shown the basic design principles work, there are lots of directions we can go with this level of precision in fabrication,” said Majumdar.

    One particularly promising direction is to progress beyond a single-surface to create a true-volume, 3D metamaterial.

    “3D-printing allows us to create a stack of these surfaces, which was not possible before,” said Majumdar.

    Co-authors are Ricky Gibson with the Air Force Research Laboratory and the University of Dayton Research Institute; Evan Smith and Joshua Hendrickson with the Air Force Research Laboratory; and James Whitehead, a UW doctoral student in the Department of Electrical and Computer Engineering. The research was funded by the National Science Foundation, the Air Force Office of Scientific Research, Samsung, the UW Reality Lab, Facebook, Google and Huawei.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    u-washington-campus
    The University of Washington is one of the world’s preeminent public universities. Our impact on individuals, on our region, and on the world is profound — whether we are launching young people into a boundless future or confronting the grand challenges of our time through undaunted research and scholarship. Ranked number 10 in the world in Shanghai Jiao Tong University rankings and educating more than 54,000 students annually, our students and faculty work together to turn ideas into impact and in the process transform lives and our world. For more about our impact on the world, every day.
    So what defines us —the students, faculty and community members at the University of Washington? Above all, it’s our belief in possibility and our unshakable optimism. It’s a connection to others, both near and far. It’s a hunger that pushes us to tackle challenges and pursue progress. It’s the conviction that together we can create a world of good. Join us on the journey.

     
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