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  • richardmitnick 7:26 am on June 26, 2017 Permalink | Reply
    Tags: , Foldscope, Manu Prakash, Stanford   

    From Stanford: “Wildly frugal – Manu Prakash’s dream is science tools for everyone, everywhere” 

    Stanford University Name
    Stanford University

    Spring 2017
    Kris Newby
    Photography by Lenny Gonzalez

    1
    Manu Prakash invents inexpensive science tools like the Foldscope, a microscope made of paper, to bring the power and joy of scientific discovery to children around the world. (Adults like them too).

    Manu Prakash’s dream is science tools for everyone, everywhere.

    Standing at the lectern in a darkened auditorium, Stanford bioengineering professor Manu Prakash told his audience that he was going to demonstrate a few low-cost scientific instruments that had been developed in his lab. He looked more like a graduate student than a professor, with his untamed hair and rumpled down jacket, as he reached into his backpack and pulled out what looked like a colorful paper bookmark.

    “This is the Foldscope,” he said, “a microscope made from 97 cents of materials.” He pointed to a tiny spherical lens at the center, and told them that they could look through it and see microscopic objects with the naked eye.

    To illustrate its magnification power, he played a video clip that had been recorded by attaching a Foldscope to a smartphone camera lens. The image of a gnat laying eggs squirmed across the auditorium’s large movie screen. Its hairy body was translucent, revealing its pulsating organs. It was like a scene from an alien horror film. A few people gasped.

    Next, he held up something that looked like a whirligig toy, a loop of twine threaded through two holes in a 3-inch-diameter disc. He grabbed the twisted ends, then rhythmically pulled. As the twine coiled and uncoiled, the disc spun at a dizzying speed. Prakash explained how he could attach a thin tube of blood along the radius of the disc and the spinning forces would separate, say, malaria parasites from blood cells, making it easy to detect the organisms under a microscope. This 20-cent, hand-powered device, called a “paperfuge” because of the prototype’s paper disc, can do the job of a $1,000 commercial centrifuge.

    Prakash was presenting at The Sequoias, a brainy retirement community nestled in the wooded foothills west of Stanford University. He had been invited to lecture on this February morning by resident Fabian Pease, PhD, an 80-year-old professor emeritus of electrical engineering at Stanford and a key collaborator on what may be Prakash’s most ambitious project yet: designing a scanning electron microscope that provides the basic functions of a $60,000 model for just $100.

    The Foldscope, the simple centrifuge and the SEM all exemplify “frugal science,” designing scientific instruments that are affordable to people in resource-poor regions. Prakash is on a mission to inspire others to create tools that will ignite the curiosity of our next generation of scientists and engineers. And it seems as if he won’t stop until every child on the planet has a backpack full of frugal science tools.

    Out of India

    Prakash’s love of invention began during his childhood in a small town in northern India. He grew up in a home where his mother, who had a PhD and taught political science at a local college, emphasized learning. Outside of school, he was encouraged to explore and invent. He and his brother loved spending time building rockets, dissecting animals, collecting unoccupied bird nests and assembling large science models.

    “This informal, curiosity-driven learning time fueled my love of science,” says Prakash.

    As an undergraduate at the Indian Institute of Technology in Kanpur, Prakash studied computer science. But he soon found that he disliked sitting in front of a computer all day. So, he began sneaking off to tinker in the robotics lab, where he built an omnidirectional walking spider-robot and a program that simulated the drawing style of children. He wanted to do more of this kind of work, and he heard that MIT was the place for inventors, so he applied and got in.

    “I just got remarkably lucky. There was no rational reason to accept me. I only had a computer science degree and I hadn’t published any papers,” says Prakash.

    At MIT, Prakash thrived. He invented a computer that used logic circuits comprised of microfluidic bubbles traveling along tiny etched canals, rather than electrons moving within metal pathways. And he worked out equations that described how water striders walk on water and how birds feed. He received his PhD in applied physics in 2008, then was awarded a Junior Fellowship at Harvard, which allowed him to pursue scholarship in any discipline for three years.

    While Prakash was visiting a health clinic in India in 2010, he saw a photo of Mahatma Gandhi that set his course. In the photo, Gandhi looks through a microscope to observe the bacteria that cause leprosy. Prakash loved the contrasts in the photo. It showed Gandhi in a loincloth, sitting cross-legged on the ground, using an expensive European microscope at a time when India was struggling to shed its dependence on all things European. The instrument was impractical for rural India, where, because of the humid climate, lenses often cloud over with mold. But Gandhi knew he needed this instrument to help fight disease in his country.

    For Prakash, this image embodies the idea that a single person embracing science during a tumultuous time can make a difference. “This is the picture that started me on my path of frugal science,” he says. He decided to spend at least half of his time as a professor developing low-cost science tools for everyone, everywhere.

    It’s a small world

    Pease, a lanky, British-born microscope lover with a full head of silver hair, first heard about Prakash at a June 2014 scientific conference in Washington, D.C. His former Stanford student Alireza Nojeh, PhD, told him over dinner about an extraordinary presentation he’d seen earlier in the day: A Stanford bioengineering professor had designed a working paper microscope that cost about a dollar. It was Prakash, who had joined Stanford’s faculty in 2011.

    2
    The Foldscope’s inventors encourage users to draw and photograph what they see through the lens and to share the images with the tool’s online community. Here’s how pollen grains from a lily look.

    Pease had to have one, so as soon as he returned to Stanford, he phoned Prakash, who happened to work in the building next door.

    “I’ve been wanting to talk to you, too,” said Prakash. “Could you help us design a $100 scanning electron microscope?”

    “It’s been tried and it can’t be done. The vacuum pumps are too expensive,” said Pease, who in 1964 wrote his PhD thesis on a high-resolution scanning electron microscope he had designed and built.

    Electrons are small, fast and difficult to control, since they obey the strange rules of quantum mechanics. Prakash knew that Pease’s expertise in harnessing electron beams would be invaluable in his pursuit of a low-cost SEM. Pease was a pioneer in developing electron beam lithography tools used to build large-scale integrated circuits. He also helped Tom Newman, his graduate student, win Nobelist Richard Feynman’s most famous physics challenge — to inscribe text small enough to fit all the pages of Encyclopedia Britannica’s 24 volumes on the head of a pin. (They did it by using electron-​beam lithography.)

    Undaunted, Prakash appealed to Pease’s love of audacious challenges: “What if we shot the electrons through a very small distance in air, so that we didn’t need vacuum pumps?”

    An SEM works on the same principle as a document scanner: by firing a precisely controlled beam back and forth across an object, measuring the intensity of the reflected beam and turning the beam into an image by layering dots on a screen. (It’s a beam of light in a scanner and of electrons in an SEM.) But SEMs work on a much, much smaller scale, which drives up costs. Generating detailed images of microscopic bacteria and viruses requires a very fine electron beam. And to keep the beam from hitting air molecules and scattering, it is fired inside an airless chamber attached to a pump and power supply.

    But instead of this costly set-up, they could shoot the beam through a sealed vacuum tube like those used in old television sets. Or they could shoot it through a very thin glass window, positioned extremely close to the desired object. If they didn’t need a 40,000-volt power supply to drive the vacuum pumps, the other microscope subsystems could be run on a trickle charge from batteries.

    For battery advice, they turned to Yi Cui, PhD, a Stanford professor of materials science and engineering. He suggested that such a battery could be made for several dollars by using conductive ink to print about 1,000 battery cells on an 8-inch-long, flexible circuit board.

    The next challenge was to figure out how to create a tight beam of electrons without using an expensive, power-hungry laser. Pease called in Nojeh, who after Stanford went on to teach engineering at the University of British Columbia. Nojeh proposed that they focus an office-supply laser pointer on an array of carbon nanotubes to create such a beam.

    At a certain point, Pease forgot how impossible the goal had seemed at first.

    “It took me back to my childhood,” says Pease. He had pulled out his old textbooks and started thinking about how to simplify everything.

    Now Pease is a regular fixture in Prakash’s lab, joining three generations of scholars dedicated to squeezing cost out of the microscope subsystems. They currently have a working test prototype.

    The primordial soup

    Many of the Prakash lab’s best ideas originate at the Friday meetings where Prakash and his 13 students brainstorm and solve problems. They are primarily biologists, physicists and engineers, but past members have included a circus performer, a music technologist and several high school students. Today, roughly half of the students are developing frugal science tools. The other half study how biological organisms function.

    Take Halteria grandinella. Prakash brought this organism into the lab accidentally, from water collected during a Foldscope testing field trip at Lake Tahoe. At a recent lab meeting, Deepak Krishnamurthy, a tall, bearded graduate student wearing nerdy black glasses, led a discussion of the single-celled creature. The aspect that most interests him is the organism’s ability to jump at speeds unheard of in the world of microbes. While he was trying to take a picture of the microbe, it disappeared from the microscope’s field of view and reappeared elsewhere, almost as if by teleportation. The organism, which lives in pond scum, is spherical with a floppy tuft of hairlike projections, called cilia. It looked like it was wearing a bad toupee.

    Prakash kicked off the discussion: “OK, let’s get this out of the way. Yes, the cilia on top look like President Trump’s hair.”

    Everyone laughed, then Krishnamurthy launched into his slide deck. Someone asked how the organism propels itself backward so quickly. Krishnamurthy waved his arms in a breast-stroke motion to show how the cilia propel the microbe slowly forward, then spun his arms like a frenzied egg-beater to show how the cilia generate explosive backward thrust. He pulled up a graph that showed velocity over time. Then he shared a dance-step diagram that traced the microbe’s pattern of motion. People argued about the purpose of the hyperspeed jumps. And for an hour, there was nothing more important than this little pond dweller.

    3
    Manu Prakash and lab members in Madagascar collect snails for a survey of a disease-causing parasite the animals spread.

    4
    Children in Tanzania build Foldscope microscopes for lessons on germ theory and sanitation.

    A million points of light

    Toward the end of his lecture at the Sequoias, Prakash pulled up a world map with pins showing where his team had shipped Foldscopes. So far, they’ve delivered 50,000 microscopes to 135 countries, beginning in 2013 with a grant from the Gordon and Betty Moore Foundation. The prototypes were funded by a Spectrum-Stanford Clinical and Translational Science Award from the National Institutes of Health.

    Prakash added, “When we ship a kit, it comes with two Foldscopes, one for you and a second one for someone who has never looked through a microscope.”

    A man in the audience asked, “Is there a temptation when you invent these things to make a lot of money?”

    “This is a philosophical question I think about,” said Prakash. “We do file patents, but we decided that we wouldn’t evaluate our success by money, but by how many people are carrying these tools in their hands.”

    To move the Foldscope from a lab-based project to a self-sustaining initiative, Prakash and Jim Cybulski, its co-​inventor​ and Prakash’s first graduate student, created a for-profit business, Foldscope Instruments, with a nonprofit subsidiary, thus enabling people with resources to subsidize those without. Their next goal is to ship 1 million Foldscopes around the world by the end of 2017. Foldscope Instruments will also commercialize other innovations from Prakash’s lab, such as the paperfuge, which was announced in January 2017, and a $5 chemistry set, announced in April 2014.

    Navi Radjou, an innovation strategist and a coauthor of the book Frugal Innovation: How to Do More with Less, says Prakash is onto something but it could take a while for people to catch on. “The Foldscope’s first benefit is in education; it’s a great way to get kids to learn by doing,” he says. “But when I talk about the Foldscope to large medical device companies, I don’t feel enthusiasm from the audience. The idea of affordable tools is a threat to their core business models.”

    Radjou adds that in the United States, there’s a perception that if something is low-cost, it’s shoddy. “It may be that the developing world will leapfrog the West in frugal innovation, because of the West’s attachment to a ‘more is better’ mentality,” he says. “The challenge is, how can Manu inspire the whole science community to embrace this concept?”

    Prakash and Cybulski have learned that it’s important to have partners in each country who can help train new users and promote the adoption of frugal science tools. To that end, Foldscope Instruments is partnering with a variety of industry, nonprofit and community groups. Through the Sigma-Aldrich Curiosity Labs initiative, they will provide students in 47 cities worldwide with Foldscopes and mentoring. To begin integrating the microscopes into Indian schools, clinics and everyday life, the Foldscope team is working with the Indian government to couple micro-research grants with free Foldscopes. They recently announced a call for proposals from Indian kids, teachers and tinkerers alike.

    “This was a special moment for me, since I deeply understand what a program like this might have meant for me as a kid growing up in a small town in India,” says Prakash.

    Near the end of his lecture at the senior center, Prakash offered to launch a Foldscope club there. He and Pease would teach the seniors how to build microscopes; then they, in turn, could teach their children and grandchildren.

    “Tell the children that everything that you touch, every experience that you have, everything that you hold, has a microscopic component,” Prakash urged them. “Every living thing is made of these living cells. And just like with astronomy, when you look through a microscope lens, there are galaxies of things crawling around.”

    As the lights in the auditorium went on, a crowd of seniors rushed the stage, each clamoring for a Foldscope.

    See the full article here .

    Please help promote STEM in your local schools.
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    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

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  • richardmitnick 7:38 am on June 20, 2017 Permalink | Reply
    Tags: , , Copper catalysts, Copper is one of the few catalysts that can produce ethanol at room temperature, Discovery could lead to sustainable ethanol made from carbon dioxide, Ethanol and propanol, , Stanford, SUNCAT Center for Interface Science and Catalysis   

    From Stanford: “Discovery could lead to sustainable ethanol made from carbon dioxide” 

    Stanford University Name
    Stanford University

    June 19, 2017
    Mark Shwartz

    1
    Thomas Jaramillo (left) & Christopher Hahn (credit: Mark Shwartz).

    “Copper is one of the few catalysts that can produce ethanol at room temperature,” he said. “You just feed it electricity, water and carbon dioxide, and it makes ethanol. The problem is that it also makes 15 other compounds simultaneously, including lower-value products like methane and carbon monoxide. Separating those products would be an expensive process and require a lot of energy.”

    Scientists would like to design copper catalysts that selectively convert carbon dioxide into higher-value chemicals and fuels, like ethanol and propanol, with few or no byproducts. But first they need a clear understanding of how these catalysts actually work. That’s where the recent findings come in.

    Copper crystals

    For the PNAS study, the Stanford team chose three samples of crystalline copper, known as copper (100), copper (111) and copper (751). Scientists use these numbers to describe the surface geometries of single crystals.

    “Copper (100), (111) and (751) look virtually identical but have major differences in the way their atoms are arranged on the surface,” said Christopher Hahn, an associate staff scientist at SLAC and co-lead lead author of the study. “The essence of our work is to understand how these different facets of copper affect electrocatalytic performance.”

    2
    Atoms aligned on the surface of copper (751) crystal. (Illustration: Christopher Hahn/SLAC National Accelerator Laboratory).

    In previous studies, scientists had created single-crystal copper electrodes just 1-square millimeter in size.

    “With such a small crystal, it’s hard to identify and quantify the molecules that are produced on the surface,” Hahn explained. “This leads to difficulties in understanding the chemical reactions, so our goal was to make larger copper electrodes with the surface quality of a single crystal.”

    To create bigger samples, Hahn and his co-workers at SLAC developed a novel way to grow single crystal-like copper on top of large wafers of silicon and sapphire.

    “What Chris did was amazing,” Jaramillo said. “He made films of copper (100), (111) and (751) with 6-square centimeter surfaces. That’s 600 times bigger than typical single crystals.

    Catalytic performance

    To compare electrocatalytic performance, the researchers placed the three large electrodes in water, exposed them to carbon dioxide gas and applied a potential to generate an electric current.

    The results were clear. When a specific voltage was applied, the electrodes made of copper (751) were far more selective to liquid products, such as ethanol and propanol, than those made of copper (100) or (111). The explanation may lie in the different ways that copper atoms are aligned on the three surfaces.

    3
    Photo: Christopher Hahn sees his reflection on the shiny surface of a copper (751) sample. (credit: Mark Shwartz).

    “In copper (100) and (111), the surface atoms are packed close together, like a square grid and a honeycomb, respectively” Hahn said. “As a result, each atom is bonded to many other atoms around it, and that tends to make the surface more inert.”

    But in copper (751), the surface atoms are further apart.

    “An atom of copper (751) only has two nearest neighbors,” Hahn said. “But an atom that isn’t bonded to other atoms is quite unhappy, and that makes it want to bind stronger to incoming reactants like carbon dioxide. We believe this is one of the key factors that lead to better selectivity to higher-value products, like ethanol and propanol.”

    Ultimately, the Stanford team would like to develop a technology capable of selectively producing carbon-neutral fuels and chemicals at an industrial scale.

    “The eye on the prize is to create better catalysts that have game-changing potential by taking carbon dioxide as a feedstock and converting it into much more valuable products using renewable electricity or sunlight directly,” Jaramillo said. “We plan to use this method on nickel and other metals to further understand the chemistry at the surface. We think this study is an important piece of the puzzle and will open up whole new avenues of research for the community.”

    Jaramillo also serves at deputy director of the SUNCAT Center for Interface Science and Catalysis, a partnership of the Stanford School of Engineering and SLAC.

    The study was also written by co-lead author Toru Hatsukade, Drew Higgins and Stephanie Nitopi at Stanford; Youn-Geun Kim at SLAC; and Jack Baricuatro and Manuel Soriaga at the California Institute of Technology.

    See the full article here .

    Please help promote STEM in your local schools.
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    Stem Education Coalition

    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

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  • richardmitnick 11:33 am on June 13, 2017 Permalink | Reply
    Tags: , Eat your vegetables, , Stanford   

    From Stanford: “Decadent-sounding descriptions could lead to higher consumption of vegetables, Stanford research finds” 

    Stanford University Name
    Stanford University

    June 12, 2017
    Milenko Martinovich

    1
    Wouldn’t you choose “sweet sizzlin’ green beans and crispy shallots” over basic green beans? According to new research from Stanford scholars, yes, indeed. (Image credit: Getty Images)

    Would you be more likely to eat vegetables if they were described as “dynamite,” “caramelized” and “sweet sizzlin’”?

    According to new research from Stanford scholars, the answer is a hearty yes.

    The study, published this week in JAMA Internal Medicine, showed that more vegetables were consumed when they were labeled with indulgent descriptions that are usually reserved for more decadent foods. The findings may help provide guidance on how to make healthier foods more appealing and encourage people to make healthier dining choices.

    Hurdles to healthy eating

    Health officials say people should eat healthier because of a growing obesity problem in the United States. According to a 2015 study by the Centers for Disease Control and Prevention’s National Center for Health Statistics, more than one-third of U.S. adults are classified as obese.

    So how do you get people to eat healthier? It’s not easy, said Bradley Turnwald, a graduate psychology student and lead author of the study. Turnwald collaborated with Alia Crum, an assistant professor of psychology and principal investigator of the Stanford Mind & Body Lab, and Danielle Boles, one of the lab’s research assistants, on the study.

    Turnwald said that previous research has shown that people tend to think that healthy foods are less tasty and less enjoyable than standard foods. Healthy foods are also perceived as less filling and less satisfying, according to prior work. A 2011 study by Crum and her colleagues found that labeling a milkshake as low-calorie and restrictive led participants to have higher levels of the hunger hormone ghrelin, compared to when participants consumed the same shake with a high-calorie and indulgent label.

    Eat your vegetables

    To test how labeling could impact consumption of healthier menu choices, the researchers collaborated with Stanford Residential & Dining Enterprises to conduct a study in a large dining hall on campus. The researchers changed how certain vegetables were labeled using four categories: basic, healthy restrictive, healthy positive or indulgent.

    Green beans, for instance, were described as “green beans” (basic), “light ’n’ low-carb green beans and shallots” (healthy restrictive), “healthy energy-boosting green beans and shallots” (healthy positive) or “sweet sizzlin’ green beans and crispy shallots” (indulgent).

    Research assistants monitored the number of diners who chose the vegetable and how much was consumed over the course of each lunch period for an entire academic quarter (46 days). There were no changes to how the food was prepared or presented throughout the study.

    The researchers found that labeling vegetables with indulgent descriptions led more diners to choose vegetables and resulted in a greater mass of vegetables served per day. Diners chose vegetables with indulgent labeling 25 percent more than basic labeling, 35 percent more than healthy positive and 41 percent more than healthy restrictive. In terms of mass of vegetables served per day, vegetables with indulgent labeling were consumed 16 percent more than those labeled healthy positive, 23 percent more than basic and 33 more than healthy restrictive.

    “We have this intuition to describe healthy foods in terms of their health attributes, but this study suggests that emphasizing health can actually discourage diners from choosing healthy options,” Turnwald said.

    A healthier future?

    This simple and low-cost strategy of altering the descriptions of healthy foods could have a substantial impact on consumption of nutritious foods in dining settings. Turnwald said more research needs to be done – he’d like to see if the effects would be similar when choosing off a restaurant menu, without the food being visible – but these findings could be the basis for a potentially effective strategy to answer a challenging question.

    “Healthy foods can be indulgent and tasty,” Turnwald said. “They just aren’t typically described that way. If people don’t think healthy foods taste good, how can we expect them to make healthy choices?”

    Said Crum: “Changing the way we label healthy foods is one step toward changing the pernicious mindset that healthy eating is depriving and distasteful.”

    This work was supported by the Robert Wood Johnson Foundation and the National Science Foundation Graduate Research Fellowship Program.

    See the full article here .

    Please help promote STEM in your local schools.
    STEM Icon

    Stem Education Coalition

    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

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  • richardmitnick 8:43 am on June 7, 2017 Permalink | Reply
    Tags: Diagrams, Eunsoo Lee, Philology, Stanford, Stanford classics student traces history of ancient geometry diagrams   

    From Stanford: “Stanford classics student traces history of ancient geometry diagrams” 

    Stanford University Name
    Stanford University

    June 5, 2017
    Alex Shashkevich,
    ashashkevich@stanford.edu,
    (650) 497-4419

    1
    Eunsoo Lee, PhD student in classics, is advancing understanding of visual knowledge by tracing the transmission and translation of diagrams in Euclid’s Elements. Detail of diagrams from a 1482 edition held by Stanford University Libraries. (Image credit: L.A. Cicero)

    Humans have been drawing lines and circles to grasp geometrical concepts and describe the laws of nature for about 5,000 years. But most scholars have approached the history of ancient mathematical sciences through close examinations of texts and writings, an area of study called philology.

    Eunsoo Lee, a PhD student in classics, hopes to expand that scholarship by tracing the changes and variations in diagrams over the course of human history.

    “Diagrams can tell us a lot about visual norms of the day,” Lee said. “Languages we speak affect how we think, but the visual images we draw also shape our thought.”

    Over the past six years, Lee has examined changes in diagrams used in Elements, a collection of 13 books on mathematical and geometric concepts attributed to Euclid, the ancient Greek mathematician who lived in Alexandria, Egypt, around 300 BCE. He is attempting to build a database of diagrams as part of his dissertation project.

    From mathematics to classics

    According to historians and scholars, Elements was deemed to be the most popular pre-20th-century textbook. The work, written about 2,300 years ago, was the second-most printed book after the Bible at one time.

    Lee first read Elements during his undergraduate years at Seoul National University, where he earned a bachelor’s degree in mathematics.

    “I was fascinated by its simple logic and structure,” said Lee, a 2016-17 Geballe Dissertation Prize Fellow at the Stanford Humanities Center. The work inspired Lee to pursue the study of classics and examine the work of other ancient scientists.

    Historians and classists have studied in detail the language of Elements – which was first written on papyrus in Greek – and how its text changed over time. But the work’s diagrams, essential to its geometrical concepts, were left out of those studies.

    “Until recently, no one has really examined the visual side of ancient science,” said Reviel Netz, professor of classics and Lee’s adviser. “You would try to recover the words that people said but you didn’t try to recover the visual impact, the images.”

    Lee was puzzled by what he calls “a blind spot” in the study of Elements and similar ancient works, some of which changed drastically over the centuries after numerous copies and translations. Lee said this puzzlement was the seed for his dissertation project at Stanford.

    Netz called Lee’s attempt to reconstruct and study the visual history of Elements unique and groundbreaking for the field of classics.

    Recent scholarship has shown that diagrams are an essential part of demonstrating the scientific meaning of an argument, Netz said.

    “We’ve come to realize just how central images are to scientific thinking,” Netz said. “You do one kind of science when you assume that diagrams are precise pictures, and you do a different kind of science when diagrams are assumed to be just rough sketches.”

    “The changes in the diagrams reflect the culture and custom of that particular age and time,” Lee said. “By examining them, we also get a better understanding of how visual knowledge has been created and transmitted.”

    Comparing diagrams

    In the course of his project, Lee has traveled numerous times to Europe to study more than 175 copies of Elements – from the earliest known Greek manuscript from the 9th century to the early printed editions in the 15th and 16th centuries.

    As Elements was reproduced over hundreds of centuries, the work was adapted for new audiences. Examining the transmission and translation of diagrams over such a long time became a vast, challenging game for Lee.

    In some cases, manuscript makers introduced errors into the diagrams that carried over to future copies. In other cases, the diagrams were meticulously transmitted and enhanced to better explain geometrical concepts to a different audience. For example, as the work’s distribution increased and parchment codex replaced papyrus rolls, what was earlier presented as one complex diagram was divided into two or more simpler drawings.

    “The diagrams were not merely copied and reproduced, but transmitted and transformed, reflecting the fashion and norms of each age,” Lee said.

    When the work was translated into Latin and Arabic from Greek, more changes were introduced. In the Arabic copies, the diagrams’ orientations and letters were switched to accommodate a right-to-left reading audience.

    But Lee also found that some Greek manuscripts carried the same switched diagrams. Lee said this finding is one of the most interesting discoveries he has made, because classics scholars overwhelmingly believe that Greek manuscripts precede the Arabic ones.

    “I believe this suggests we have to open the possibility that some Arabic diagrams might have influenced the early Greek diagrams,” Lee said.

    The printing revolution in the 15th century marked a significant footprint in the history of diagrams, Lee said. The makers of the diagrams, who were previously largely unknown, became recognized as authors. The diagrams themselves became exposed to competition, he said.

    “The competition naturally resulted in diagrammatic criticism and led to the invention of more practical drawing of diagrams to attract more readers,” Lee said.

    A ‘lifelong’ project

    Aside from tracing the changes in diagrams themselves, Lee is also trying to develop a framework for how to distinguish them and record their differences.

    “The methodology for examining diagrams remains in its infancy,” Lee said. “And there is no consensus regarding how it might address the reconstruction, comparison and tracing of diagrams, which therefore are neither acknowledged nor investigated in any significant depth.”

    Lee hopes to continue to trace the history of visual knowledge and expand his analysis beyond Elements. But he recognizes that the task is of enormous proportions, particularly because of the need to examine a large number of ancient texts, most of which remain scattered across libraries in different countries and are available for limited viewing.

    “It’s a huge project,” Lee said. “It’s a lifelong plan.”

    See the full article here .

    Please help promote STEM in your local schools.
    STEM Icon

    Stem Education Coalition

    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

     
  • richardmitnick 5:53 pm on June 1, 2017 Permalink | Reply
    Tags: , , Stanford   

    From Stanford: “High pressure key to lighter, stronger metal alloys, Stanford scientists find” 

    Stanford University Name
    Stanford University

    May 25, 2017
    Ker Than

    Subjecting complex metal mixtures called high-entropy alloys to extremely high pressures could lead to finer control over the arrangement of their atoms, which in turn can result in more desirable properties.

    1
    Simple alloys like the molten steel in this factory are usually composed of just one or two dominant metals. But a new Stanford study shows that high pressure could be used to control the final properties of advanced, high-entropy alloys that have five or more mixed metals. (Image credit: Shutterstock)

    High pressure could be the key to making advanced metal mixtures that are lighter, stronger and more heat-resistant than conventional alloys, a new study [Nature] by Stanford researchers suggests.

    Humans have been blending metals together to create alloys with unique properties for thousands of years. But traditional alloys typically consist of one or two dominant metals with a pinch of other metals or elements thrown in. Classic examples include adding tin to copper to make bronze, or carbon to iron to create steel.

    In contrast, “high-entropy” alloys consist of multiple metals mixed in approximately equal amounts. The result is stronger and lighter alloys that are more resistant to heat, corrosion and radiation, and that might even possess unique mechanical, magnetic or electrical properties.

    Despite significant interest from material scientists, high-entropy alloys have yet to make the leap from the lab to actual products. One major reason is that scientists haven’t yet figured out how to precisely control the arrangement, or packing structure, of the constituent atoms. How an alloy’s atoms are arranged can significantly influence its properties, helping determine, for example, whether it is stiff or ductile, strong or brittle.

    “Some of the most useful alloys are made up of metal atoms arranged in a combination of packing structures,” said study first author Cameron Tracy, a postdoctoral researcher at Stanford’s School of Earth, Energy & Environmental Sciences and the Center for International Security and Cooperation (CISAC).

    A new structure

    To date, scientists have only been able to re- create two types of packing structures with most high-entropy alloys, called body-centered cubic and face-centered cubic. A third, common packing structure has largely eluded scientists’ efforts — until now.

    In the new study, published online in the journal Nature Communications, Tracy and his colleagues report that they have successfully created a high-entropy alloy, made of common and readily available metals, with a so-called hexagonal close-packed (HCP) structure.

    “A small number of high-entropy alloys with the HCP structure have been made in the last few years, but they contain a lot of exotic elements such as alkali metals and rare earth metals,” Tracy said. “What we managed to do is to make an HCP high-entropy alloy from common metals that are typically used in engineering applications.”

    The trick, it appears, is high pressure. Tracy and his colleagues used an instrument called a diamond-anvil cell to subject tiny samples of a high-entropy alloy to pressures as high as 55 gigapascals – roughly the pressure one would encounter in the Earth’s mantle. “The only time you would ever naturally see that pressure on the Earth’s surface is during a really big meteorite impact,” Tracy said.

    High pressure appears to trigger a transformation in the high-entropy alloy the team used, which consisted of manganese, cobalt, iron, nickel and chromium. “Imagine the atoms as a layer of ping pong balls on a table, and then adding more layers on top. That can form a face-centered cubic packing structure. But if you shift some of the layers slightly relative to the first one, you would get a hexagonal close-packed structure,” Tracy said.

    Scientists have speculated that the reason high-entropy alloys don’t undergo this shift naturally is because interacting magnetic forces between the metal atoms prevent it from happening. But high pressure seems to disrupt the magnetic interactions.

    “When you pressurize a material, you push all of the atoms closer together. Oftentimes, when you compress something, it becomes less magnetic,” Tracy said. “That’s what appears to be happening here: compressing the high-entropy alloy makes it non-magnetic or close to non-magnetic, and an HCP phase is suddenly possible.”
    Stable configuration

    Interestingly, the alloy retains an HCP structure even after the pressure is removed. “Most of the time, when you take the pressure away, the atoms snap back to their previous configuration. But that’s not happening here, and that’s really surprising,” said study coauthor Wendy Mao, an associate professor of geological sciences at Stanford’s School of Earth, Energy & Environmental Sciences.

    The team also discovered that by slowly cranking up the pressure, they could increase the amount of hexagonal close-pack structure in their alloy. “This suggests it’s possible to tailor the material to give us exactly the mechanical properties that we want for a particular application,” Tracy said.

    For example, combustion engines and power plants run more efficiently at high temperatures but conventional alloys tend to not perform well in extreme conditions because their atoms start moving around and become more disordered.

    “High-entropy alloys, however, already possess a high degree of disorder due to their highly intermingled natures,” Tracy said. “As a result, they have mechanical properties that are great at low temperatures and stay great at high temperatures.”

    In the future, materials scientists may be able to fine-tune the properties of high-entropy alloys even further by mixing different metals and elements together. “There’s a huge part of the periodic table and so many permutations to be explored,” Mao said.

    Other Stanford coauthors on the study include Rodney Ewing, senior fellow at the Stanford Freeman Spogli Institute for International Studies and a professor of geological and environmental sciences; and graduate students Sulgiye Park and Dylan Rittman; and colleagues at the University of Tennessee and Oak Ridge National Laboratory. Funding was provided by the U.S. Department of Energy and the National Science Foundation.

    See the full article here .

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    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

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  • richardmitnick 11:35 am on May 31, 2017 Permalink | Reply
    Tags: , , New Stanford center will advance vision research, Stanford   

    From Stanford: “New Stanford center will advance vision research” 

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    Stanford University

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    Scope blog

    May 30, 2017
    Becky Bach

    Excellent news broke this morning: Stanford University will be establishing a new vision research center to develop therapies to prevent the loss of vision and to restore sight.

    Established with a gift from Mary Spencer, it will be called the Mary M. and Sash A. Spencer Center for Vision Research, named in honor of her late husband, Sash. Spencer, who suffers from macular degeneration, said she was inspired, in part, by Jeffrey Goldberg‘s work using nanoparticles to help restore eye function. Goldberg, MD, PhD, has led the Department of Ophthalmology since 2015.

    A press release captured reactions from Stanford Medicine leaders:

    Lloyd Minor, MD, dean of the School of Medicine, said, ‘We are optimistic that with the establishment of this new center, significant advances in vision science will be translated into improved patient care, transforming the lives of millions suffering from eye disease the world over.’ …

    [Goldberg said:] ‘Many diseases of the eye still lack clear and effective methods of prevention, treatment or cure. Although much research is underway, bridging the chasm from the lab to clinical testing and ultimately to proven therapies remains the core challenge to making real progress.

    Our goal for this new center is to bring together teams of interdisciplinary experts in genetics, imaging, stem cell and neurobiology with leaders in vision science. By harnessing the combined talents and energy available at Stanford and beyond, we can uncover novel therapies and bring them more rapidly to human trials — to real patients — so that others can benefit in the nearer term.’

    The center will be located at the Byers Eye Institute.

    Previously: Stanford scientists describe stem-cell and gene-therapy advances in scientific symposium, Successful replacement of eye cells hints at future glaucoma treatment and Thousands of queries, added funds fuel pushoff from successful Stanford vision-restoration study

    See the full article here .

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    Scope is an award-winning blog founded in 2009 and produced by the Stanford University School of Medicine. If you’re curious about the latest advances in medicine and health and enjoy compelling, fresh and easily digestible news and features, then we’ve got just the thing. We’ve written quite a bit (7,000 posts and counting!), and we’re quite proud of it — so please enjoy.

    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

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  • richardmitnick 1:49 pm on May 27, 2017 Permalink | Reply
    Tags: , , CLARITY, Stanford   

    From Stanford- “Karl Deisseroth: How we can better understand the brain’s circuitry” 

    Stanford University Name
    Stanford University

    July 19, 2016 [Finally brought it out to play.]
    Vignesh Ramachandran

    1
    A new technique helps researchers study the connections between neurons. iStock/from2015

    How much about the human brain do we really know? Not enough, says bioengineer Karl Deisseroth. A milky, opaque tissue coats much of the organ, preventing researchers from seeing the all-important connections between neurons. So Deisseroth’s team developed a way to remove this cloud by chemically dissolving the opaque fatty tissue in a dead brain and replacing it with a transparent hydrogel.

    This technique, called CLARITY gives researchers an unprecedented ability to study the neurostructure and circuitry of the brain. “Our goal is to understand the system in its entirety but also at high resolution,” says Deisseroth, the D.H. Chen Professor in Stanford School of Medicine and a professor of bioengineering and of psychiatry and behavioral sciences.


    The accompanying video, produced by Miles O’Brien and Ann Kellan of Science Nation, and published here with permission by Stanford Engineering, shows how CLARITY could lead to new treatments for conditions like depression, and pave the way for medical advances outside the brain such as offering researchers new ways to understand electrical pathways in the heart or learn why damaged fibers in the spinal cord cause pain.

    See the full article here .

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    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

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  • richardmitnick 7:28 am on May 12, 2017 Permalink | Reply
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    From Stanford: “Despite a popular media story, rumors of inflationary theory’s demise is premature, Stanford researchers say” 

    Stanford University Name
    Stanford University

    May 10, 2017
    Amy Adams

    From the earliest human civilizations, people have looked to the heavens and pondered the origins of the stars and constellations above. Once, those stories involved gods and magical beings. Now, there’s science, and a large research enterprise focused on understanding how the universe came to be.

    1
    Professor Andrei Linde is among the physicists responding to a recent media story taking aim at inflationary theory. (Image credit: L.A. Cicero)

    Squarely in the center of this research enterprise is what’s known as inflationary theory. It argues that the universe was born out of an unstable, energetic vacuum-like state then expanded dramatically, spinning off entire galaxies produced by quantum fluctuations. This theory was proposed in 1980 by Alan Guth, presently at MIT.

    2
    Alan Guth: https://alchetron.com/Alan-Guth-589833-W

    A year later, this theory was improved and extended by Andrei Linde, Stanford professor of physics, who has spent a lifetime modifying and updating it as new data emerged.

    During the last 35 years, many predictions of inflationary theory have been verified by theorists and confirmed by cosmological observations. Gradually, this theory became a generally accepted description of the origin of the universe. So imagine Linde’s surprise when Scientific American published a story in February by Paul Steinhardt, a professor of physics at Princeton, and his colleagues declaring its demise.

    In response, Linde and Guth, along with their colleagues David Kaiser from MIT and Yasunori Nomura from the University of California, Berkeley, have written a letter [Scientific American] defending the inflationary theory, published in Scientific American May 10. It was signed by 33 academics who read like a Who’s Who of theoretical physicists, including Stephen Hawking of Cambridge University. In it, they take aim at the primary argument in the story: that inflationary theory isn’t really a scientific theory because it doesn’t predict anything and therefore can’t be tested.

    “As the work of several major, international collaborations has made clear, inflation is not only testable but it has been subjected to a significant number of tests and so far has passed every one,” the group wrote.

    A flat universe

    As one example, the inflationary model had predicted that if the universe is ever expanding, it would now be flat rather than open or closed. (Imagine a balloon growing infinitely large. Eventually its surface would appear completely flat.) A flat universe would be represented by a variable called Omega that is equal to 1, “Well, plus or minus a little bit because of quantum uncertainty,” Linde said.

    In fact, in the mid-’90s many astrophysicists believed that the universe was actually not flat, with an Omega closer to about 0.3. “That would be a disaster for inflation,” Linde said. He then tried to find the flaw in his own theory. However, all attempts to construct a model of inflation with Omega equal 0.3 were unsuccessful; the proposed modifications of inflationary theory were extremely complicated and unnatural, and most of them simply did not work. Fortunately, in 1998, a series of cosmological observations revealed the existence of dark energy. It turned out that the energy of a vacuum is not zero, as previously thought, and Omega was restored to 1.

    “If inflationary theory can’t predict anything, why could it appear to be dead when a prediction turned out not to be true?” Linde asked. And how could it be restored by new data that validated the prediction?

    A tense time

    A similarly dramatic situation emerged five years ago, when rumors circulated about a fairly technical issue that’s known as the Gaussianity of inflationary perturbations. The main thing to know about Gaussianity is that the discovery of a large non-Gaussianity of a specific type would rule out 99.9% of the existing inflationary models.

    In 2012 and winter 2013, there were persistent rumors that this non-Gaussianity would soon to be reported by the Planck satellite, and in fact preliminary data by the WMAP satellite indicated a possibility of a very large non-Gaussianity. If that had turned out to be true, it could be a crucial blow to the inflationary theory.

    However, the Planck data revealed no traces of non-Gaussianity. The very last sentence of the Planck paper describing that data read, “With these results, the paradigm of standard single-field slow-roll inflation has survived its most stringent tests to-date.”

    This and many other successful predictions of inflationary theory are undeniable facts, Linde said. “If we trust the arguments made in the Scientific American story, all successful predictions of inflationary cosmology are the result of pure luck, like winning the lottery,” Linde said. “One can do that once, twice, but not this many times. That is why so many leaders of modern physics signed our letter.”

    Linde added that the letters section of a popular magazine is not normally where scientific debate plays out. “A long time ago, when I was young and naive, I thought that things like that are impossible in science,” he said. Now, he just hopes people see that the opinions in the story are not shared by many of the biggest names in theoretical physics and observational cosmology.

    Linde added that he worries about the younger generation of scientists getting the wrong impression from this story. “I don’t want them to read this article and think that they are spending their time on inflationary theory in vain. But the enthusiastic support that we are receiving makes us optimistic that this is not going to happen,” he said.

    See the full article here .

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    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

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  • richardmitnick 8:56 am on May 10, 2017 Permalink | Reply
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    From Stanford: “Stanford team brings quantum computing closer to reality with new materials” 

    Stanford University Name
    Stanford University

    May 9, 2017
    Tom Abate

    1
    Researchers are developing quantum computers based on light rather than electricity. At Stanford, new materials could be the key to progress in this field. (Image credit: iStock/Pobytov)

    For 60 years computers have become smaller, faster and cheaper. But engineers are approaching the limits of how small they can make silicon transistors and how quickly they can push electricity through devices to create digital ones and zeros.

    That limitation is why Stanford electrical engineering Professor Jelena Vuckovic is looking to quantum computing, which is based on light rather than electricity. Quantum computers work by isolating spinning electrons inside a new type of semiconductor material. When a laser strikes the electron, it reveals which way it is spinning by emitting one or more quanta, or particles, of light. Those spin states replace the ones and zeros of traditional computing.

    Vuckovic, who is one of the world’s leading researchers in the field, said quantum computing is ideal for studying biological systems, doing cryptography or data mining – in fact, solving any problem with many variables.

    “When people talk about finding a needle in a haystack, that’s where quantum computing comes in,” she said.

    Marina Radulaski, a postdoctoral fellow in Vuckovic’s lab, said the problem-solving potential of quantum computers stems from the complexity of the laser-electron interactions at the core of the concept.

    “With electronics you have zeros and ones,” Radulaski said. “But when the laser hits the electron in a quantum system, it creates many possible spin states, and that greater range of possibilities forms the basis for more complex computing.”

    Capturing electrons

    Harnessing information based on the interactions of light and electrons is easier said than done. Some of the world’s leading technology companies are trying to build massive quantum computers that rely on materials super-cooled to near absolute zero, the theoretical temperature at which atoms would cease to move.

    In her own studies of nearly 20 years, Vuckovic has focused on one aspect of the challenge: creating new types of quantum computer chips that would become the building blocks of future systems.

    “To fully realize the promise of quantum computing we will have to develop technologies that can operate in normal environments,” she said. “The materials we are exploring bring us closer toward finding tomorrow’s quantum processor.”

    The challenge for Vuckovic’s team is developing materials that can trap a single, isolated electron. Working with collaborators worldwide, they have recently tested three different approaches to the problem, one of which can operate at room temperature – a critical step if quantum computing is going to become a practical tool.

    In all three cases the group started with semiconductor crystals, material with a regular atomic lattice like the girders of a skyscraper. By slightly altering this lattice, they sought to create a structure in which the atomic forces exerted by the material could confine a spinning electron.

    “We are trying to develop the basic working unit of a quantum chip, the equivalent of the transistor on a silicon chip,” Vuckovic said.

    Quantum dots

    One way to create this laser-electron interaction chamber is through a structure known as a quantum dot. Physically, the quantum dot is a small amount of indium arsenide inside a crystal of gallium arsenide. The atomic properties of the two materials are known to trap a spinning electron.

    In a recent paper in Nature Physics, Kevin Fischer, a graduate student in the Vuckovic lab, describes how the laser-electron processes can be exploited within such a quantum dot to control the input and output of light. By sending more laser power to the quantum dot, the researchers could force it to emit exactly two photons rather than one. They say the quantum dot has practical advantages over other leading quantum computing platforms but still requires cryogenic cooling, so it may not be useful for general-purpose computing. However, it could have applications in creating tamper-proof communications networks.

    Color centers

    In two other papers Vuckovic took a different approach to electron capture, by modifying a single crystal to trap light in what is called a color center.

    In a recent paper published in NanoLetters, her team focused on color centers in diamond. In nature the crystalline lattice of a diamond consists of carbon atoms. Jingyuan Linda Zhang, a graduate student in Vuckovic’s lab, described how a 16-member research team replaced some of those carbon atoms with silicon atoms. This one alteration created color centers that effectively trapped spinning electrons in the diamond lattice.

    But like the quantum dot, most diamond color center experiments require cryogenic cooling. Though that is an improvement over other approaches that required even more elaborate cooling, Vuckovic wanted to do better.

    So she worked with another global team to experiment with a third material, silicon carbide. Commonly known as carborundum, silicon carbide is a hard, transparent crystal used to make clutch plates, brake pads and bulletproof vests. Prior research had shown that silicon carbide could be modified to create color centers at room temperature. But this potential had not yet been made efficient enough to yield a quantum chip.

    Vuckovic’s team knocked certain silicon atoms out of the silicon carbide lattice in a way that created highly efficient color centers. They also fabricated nanowire structures around the color centers to improve the extraction of photons. Radulaski was the first author on that experiment, which is described in another NanoLetters paper. She said the net results – an efficient color center, operating at room temperature, in a material familiar to industry – were huge pluses.

    “We think we’ve demonstrated a practical approach to making a quantum chip,” Radulaski said.

    But the field is still in its early days and electron tapping is no simple feat. Even the researchers aren’t sure which method or methods will win out.

    “We don’t know yet which approach is best, so we continue to experiment,” Vuckovic said.

    The diamond research team included Stanford faculty members Zhi-Xun Shen, the Paul Pigott Professor in Physical Sciences, professor of photon science, of physics and of applied physics, and a senior fellow at the Precourt Institute for Energy; Nicholas Melosh, an associate professor of materials science and engineering and of photon science; and Steven Chu, the William R. Kenan Jr. Professor, professor of physics and of molecular and cellular physiology, and member of Stanford Bio-X and the Stanford Neurosciences Institute.

    See the full article here .

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    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

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  • richardmitnick 9:19 am on April 10, 2017 Permalink | Reply
    Tags: , , , Nanoporous materials, , , Stanford, Stanford scientist’s new approach may accelerate design of high-power batteries, Storing electricity, Supercapacitors   

    From Stanford: “Stanford scientist’s new approach may accelerate design of high-power batteries” 

    Stanford University Name
    Stanford University

    April 6, 2017
    Danielle Torrent Tucker

    1
    Electric vehicles plug in to charging stations. New research may accelerate discovery of materials used in electrical storage devices, such as car batteries. (Image credit: Shutterstock)

    In work published this week in Applied Physics Letters, the researchers describe a mathematical model for designing new materials for storing electricity. The model could be a huge benefit to chemists and materials scientists, who traditionally rely on trial and error to create new materials for batteries and capacitors. Advancing new materials for energy storage is an important step toward reducing carbon emissions in the transportation and electricity sectors.

    “The potential here is that you could build batteries that last much longer and make them much smaller,” said study co-author Daniel Tartakovsky, a professor in the School of Earth, Energy & Environmental Sciences. “If you could engineer a material with a far superior storage capacity than what we have today, then you could dramatically improve the performance of batteries.”

    Lowering a barrier

    One of the primary obstacles to transitioning from fossil fuels to renewables is the ability to store energy for later use, such as during hours when the sun is not shining in the case of solar power. Demand for cheap, efficient storage has increased as more companies turn to renewable energy sources, which offer significant public health benefits.

    Tartakovsky hopes the new materials developed through this model will improve supercapacitors, a type of next-generation energy storage that could replace rechargeable batteries in high-tech devices like cellphones and electric vehicles. Supercapacitors combine the best of what is currently available for energy storage – batteries, which hold a lot of energy but charge slowly, and capacitors, which charge quickly but hold little energy. The materials must be able to withstand both high power and high energy to avoid breaking, exploding or catching fire.

    “Current batteries and other storage devices are a major bottleneck for transition to clean energy,” Tartakovsky said. “There are many people working on this, but this is a new approach to looking at the problem.”

    The types of materials widely used to develop energy storage, known as nanoporous materials, look solid to the human eye but contain microscopic holes that give them unique properties. Developing new, possibly better nanoporous materials has, until now, been a matter of trial and error – arranging minuscule grains of silica of different sizes in a mold, filling the mold with a solid substance and then dissolving the grains to create a material containing many small holes. The method requires extensive planning, labor, experimentation and modifications, without guaranteeing the end result will be the best possible option.

    “We developed a model that would allow materials chemists to know what to expect in terms of performance if the grains are arranged in a certain way, without going through these experiments,” Tartakovsky said. “This framework also shows that if you arrange your grains like the model suggests, then you will get the maximum performance.”

    Beyond energy

    Energy is just one industry that makes use of nanoporous materials, and Tartakovsky said he hopes this model will be applicable in other areas, as well.

    “This particular application is for electrical storage, but you could also use it for desalination, or any membrane purification,” he said. “The framework allows you to handle different chemistry, so you could apply it to any porous materials that you design.”

    Tartakovsky’s mathematical modeling research spans neuroscience, urban development, medicine and more. As an Earth scientist and professor of energy resources engineering, he is an expert in the flow and transport of porous media, knowledge that is often underutilized across disciplines, he said. Tartakovsky’s interest in optimizing battery design stemmed from collaboration with a materials engineering team at the University of Nagasaki in Japan.

    “This Japanese collaborator of mine had never thought of talking to hydrologists,” Tartakovsky said. “It’s not obvious unless you do equations – if you do equations, then you understand that these are similar problems.”

    The lead author of the study, “Optimal design of nanoporous materials for electrochemical devices,” is Xuan Zhang, Tartakovsky’s former PhD student at the University of California, San Diego. The research was supported by the Defense Advanced Research Projects Agency and the National Science Foundation.

    See the full article here .

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    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

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