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  • richardmitnick 3:20 pm on October 29, 2014 Permalink | Reply
    Tags: , , , Energy, ,   

    From LBL: “New Lab Startup Afingen Uses Precision Method to Enhance Plants” 

    Berkeley Logo

    Berkeley Lab

    October 29, 2014
    Julie Chao (510) 486-6491

    Imagine being able to precisely control specific tissues of a plant to enhance desired traits without affecting the plant’s overall function. Thus a rubber tree could be manipulated to produce more natural latex. Trees grown for wood could be made with higher lignin content, making for stronger yet lighter-weight lumber. Crops could be altered so that only the leaves and certain other tissues had more wax, thus enhancing the plant’s drought tolerance, while its roots and other functions were unaffected.

    By manipulating a plant’s metabolic pathways, two scientists at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), Henrik Scheller and Dominique Loqué, have figured out a way to genetically rewire plants to allow for an exceptionally high level of control over the spatial pattern of gene expression, while at the same time boosting expression to very high levels. Now they have launched a startup company called Afingen to apply this technology for developing low-cost biofuels that could be cost-competitive with gasoline and corn ethanol.

    two
    Henrik Scheller (left) and Dominique Loque hold a tray of Arabidopsis Thaliana plants, which they used in their research. (Berkeley Lab photo)

    “With this tool we seem to have found a way to control very specifically what tissue or cell type expresses whatever we want to express,” said Scheller. “It’s a new way that people haven’t thought about to increase metabolic pathways. It could be for making more cell wall, for increasing the stress tolerance response in a specific tissue. We think there are many different applications.”

    Cost-competitive biofuels

    Afingen was awarded a Small Business Innovation Research (SBIR) grant earlier this year for $1.72 million to engineer switchgrass plants that will contain 20 percent more fermentable sugar and 40 percent less lignin in selected structures. The grant was provided under a new SBIR program at DOE that combines an SBIR grant with an option to license a specific technology produced at a national laboratory or university through DOE-supported research.

    “Techno-economic modeling done at (the Joint BioEnergy Institute, or JBEI) has shown that you would get a 23 percent reduction in the price of the biofuel with just a 20 percent reduction in lignin,” said Loqué. “If we could also increase the sugar content and make it easier to extract, that would reduce the price even further. But of course it also depends on the downstream efficiency.”

    Scheller and Loqué are plant biologists with the Department of Energy’s Joint BioEnergy Institute (JBEI), a Berkeley Lab-led research center established in 2007 to pursue breakthroughs in the production of cellulosic biofuels. Scheller heads the Feedstocks Division and Loqué leads the cell wall engineering group.

    The problem with too much lignin in biofuel feedstocks is that it is difficult and expensive to break down; reducing lignin content would allow the carbohydrates to be released and converted into fuels much more cost-effectively. Although low-lignin plants have been engineered, they grow poorly because important tissues lack the strength and structural integrity provided by the lignin. With Afingen’s technique, the plant can be manipulated to retain high lignin levels only in its water-carrying vascular cells, where cell-wall strength is needed for survival, but low levels throughout the rest of the plant.

    The centerpiece of Afingen’s technology is an “artificial positive feedback loop,” or APFL. The concept targets master transcription factors, which are molecules that regulate the expression of genes involved in certain biosynthetic processes, that is, whether certain genes are turned “on” or “off.” The APFL technology is a breakthrough in plant biotechnology, and Loqué and Scheller recently received an R&D 100 Award for the invention.

    An APFL is a segment of artificially produced DNA coded with instructions to make additional copies of a master transcription factor; when it is inserted at the start of a chosen biosynthetic pathway—such as the pathway that produces cellulose in fiber tissues—the plant cell will synthesize the cellulose and also make a copy of the master transcription factor that launched the cycle in the first place. Thus the cycle starts all over again, boosting cellulose production.

    The process differs from classical genetic engineering. “Some people distinguish between ‘transgenic’ and ‘cisgenic.’ We’re using only pieces of DNA that are already in that plant and just rearranging them in a new way,” said Scheller. “We’re not bringing in foreign DNA.”

    Other licensees and applications

    This breakthrough technique can also be used in fungi and for a wide variety of uses in plants, for example, to increase food crop yields or to boost production of highly specialized molecules used by the pharmaceutical and chemical industries. “It could also increase the quality of forage crops, such as hay fed to cows, by increasing the sugar content or improving the digestibility,” Loqué said.

    Another intriguing application is for biomanufacturing. By engineering plants to grow entirely new pharmaceuticals, specialty chemicals, or polymer materials, the plant essentially becomes a “factory.” “We’re interested in using the plant itself as a host for production,” Scheller said. “Just like you can upregulate pathways in plants that make cell walls or oil, you can also upregulate pathways that make other compounds or properties of interest.”

    Separately, two other companies are using the APFL technology. Tire manufacturer Bridgestone has a cooperative research and development agreement (CRADA) with JBEI to develop more productive rubber-producing plants. FuturaGene, a Brazilian paper and biomass company, has licensed the technology for exclusive use with eucalyptus trees and several other crops; APFL can enhance or develop traits to optimize wood quality for pulping and bioenergy applications.

    “The inventors/founders of Afingen made the decision to not compete for a license in fields of use that were of interest to other companies that had approached JBEI. This allowed JBEI to move the technology forward more quickly on several fronts,” said Robin Johnston, Berkeley Lab’s Acting Deputy Chief Technology Transfer Officer. “APFL is a very insightful platform technology, and I think only a fraction of the applications have even been considered yet.”

    Afingen currently has one employee—Ai Oikawa, a former postdoctoral researcher and now the director of plant engineering—and will be hiring three more in November. It is the third startup company to spin out of JBEI. The first two were Lygos, which uses synthetic biology tools to produce chemical compounds, and TeselaGen, which makes tools for DNA synthesis and cloning.

    See the full article here.

    A U.S. Department of Energy National Laboratory Operated by the University of California

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  • richardmitnick 3:35 pm on October 27, 2014 Permalink | Reply
    Tags: , , Energy, , ,   

    From AAAS: “After Election 2014: FUSION RESEARCH” 

    AAAS

    AAAS

    ScienceInsider

    24 October 2014
    Adrian Cho

    Should we stay or should we go? Once the voters have spoken, that’s the question Congress will have to answer regarding the United States’ participation in ITER, the hugely overbudget fusion experiment under construction in Cadarache, France. Some lawmakers say it may be time for the United States to bow out, especially as the growing ITER commitment threatens to starve U.S.-based fusion research programs. The next Congress may have to decide the issue—if the current one doesn’t pull the plug first when it returns to Washington, D.C., for a 6-week lame-duck session.

    ITER Tokamak
    ITER Tokamak

    For those tired of the partisan squabbling on Capitol Hill, the ITER debate may provide curious relief. ITER appears to enjoy bipartisan support in the House of Representatives—and bipartisan opposition among key senators.

    ITER aims to prove that nuclear fusion is a viable source of energy, and the United States has agreed to build 9% of the reactor’s hardware, regardless of the cost. Recent estimates suggest the U.S. price tag could be $3.9 billion or more—nearly quadrupling original estimates and raising alarm among some lawmakers. In response, this past June a Senate appropriations subcommittee proposed a budget bill that would end U.S. participation in the project next year. In contrast, the next month the House passed a bill that would increase U.S. spending on ITER.

    Some observers think the current Congress will kick the issue to the next one by passing a stop-gap budget for fiscal year 2015, which began 1 October, that will keep U.S. ITER going. “I don’t think in the end they can come out and kill ITER based on what the Senate subcommittee did,” says Stephen Dean, president of Fusion Power Associates, a research and educational foundation in Gaithersburg, Maryland. Others say a showdown could come by year’s end.

    Trouble over ITER has been brewing for years. ITER was originally proposed in 1985 as a joint U.S.-Soviet Union venture. The United States backed out of the project in 1998 because of cost and schedule concerns—only to rejoin in 2003. At the time, ITER construction costs were estimated at $5 billion. That number had jumped to $12 billion by 2006, when the European Union, China, India, Japan, Russia, South Korea, and the United States signed a formal agreement to build the device. At the time, ITER was supposed to start running in 2016. By 2011, U.S. costs for ITER had risen to more than $2 billion, and the date for first runs had slid to 2020. But even that date was uncertain; U.S. ITER researchers did not have a detailed cost projection and schedule—or performance baseline—to go by.

    Then in 2013, the Department of Energy (DOE) argued in its budget request for the following year that U.S. ITER was not a “capital asset” and therefore did not have to go through the usual DOE review process for large construction projects—which requires a performance baseline. Even though DOE promised to limit spending on ITER to $225 million a year so as not to starve domestic fusion research efforts, that statement irked Senators Dianne Feinstein (D–CA) and Lamar Alexander (R–TN), the chair and ranking member of the Senate Appropriations Subcommittee on Energy and Water Development, respectively. They and other senators asked the Government Accountability Office (GAO) to investigate the U.S. ITER project.

    This year, things appeared to come to a head. This past April, researchers working on U.S. ITER released their new $3.9 billion cost estimate and moved back the date for first runs to 2024 or later. Two months later, GAO reported that even that new estimate was not reliable and that the cost to the United States could reach $6.5 billion. Based on that report, the Senate energy and water subcommittee moved to kill U.S. ITER in its markup of the proposed 2015 budget, giving it only $75 million for the year, half of what the White House had requested and just enough to wind things down. Alexander supported the move, even though the U.S. ITER office is based in his home state of Tennessee, at Oak Ridge National Laboratory.

    ITER still has friends in the House, however. In their version of the DOE budget for 2015, House appropriators gave ITER $225 million, $75 million more than the White House request. Moreover, the project seems to have bipartisan support in the House, as shown by a hearing of the energy subcommittee of the House Committee on Science, Space, and Technology. Usually deeply divided along party lines, the subcommittee came together to lavish praise on ITER, with representative Lamar Smith (R–TX), chair of the full committee, and Representative Eric Swalwell (D–CA), the ranking member on the subcommittee, agreeing that ITER was, in Swalwell’s words, “absolutely essential to proving that magnetically confined fusion can be a viable clean energy source.” Swalwell called for spending more than $225 million per year on ITER.

    When and how this struggle over ITER plays out depends on the answers to several questions. First, how will Congress deal with the already late budget for next year? The Senate, controlled by the Democrats, has yet to pass any of its 13 budget bills, including the one that would fund energy research. And if the House and Senate decide to simply continue the 2014 budget past the end of the year, then the decision on ITER will pass to the next Congress. If, on the other hand, Congress passes a last-minute omnibus budget for fiscal year 2015, then the fight over ITER could play out by year’s end.

    Second, how sincere is the Senate move to kill ITER? The Senate subcommittee’s move may have been meant mainly to send a signal to the international ITER organization that it needs to shape up, says one Democratic staffer in the House. The international ITER organization received scathing criticism in an independent review in October 2013. That review called for 11 different measures to overhaul the project’s management, and the Senate’s markup may have been meant primarily to drive home the message that those measures had to be taken to ensure continued U.S. involvement, the staffer says.

    Third, how broad is the House’s support for ITER? Over the past decade or so, the House has been more supportive of fusion in general, the Democratic staffer says. But some observers credit that support mainly to one person, Representative Rodney Frelinghuysen (R-NJ), a longtime member of the House Appropriations Committee. “Over the years he’s become a champion of fusion,” Dean says. “He protects it in the House.” Dean and others say that’s likely because the DOE’s sole dedicated fusion laboratory, the Princeton Plasma Physics Laboratory (PPPL), is in his home state of New Jersey (but not Frelinghuysen’s district).

    Indeed, observers say that Frelinghuysen has been instrumental in preventing cuts to the domestic fusion program proposed by DOE itself. For example, for fiscal 2014, DOE requested $458 million for its fusion energy sciences program, including $225 million for ITER. That meant cutting the domestic fusion program by about 20% to $233 million and closing one of three tokamak reactors in the United States. The Senate went along with those numbers, but House appropriators bumped the budget up to $506 million, the number that held sway in the final 2014 spending plan. But some observers speculate that Frelinghuysen might be willing to let ITER go if he could secure a brighter future for PPPL.

    PPPL Tokamak
    PPPL Tokamak

    PPPL NSTX
    PPPL National Spherical Torus Experiment

    Finally, the biggest question surrounding U.S. participation in ITER is: How will the international ITER organization respond to the calls for changes in its management structure? That should become clear within months. So far, officials with U.S. ITER have not been able to produce a baseline cost estimate and schedule in large measure, because the ITER project as a whole does not have a reliable schedule. The international ITER organization has said it will produce one by next July, the House staffer says. And if the international organization doesn’t produce a credible schedule, the staffer says, “the project will be very difficult to defend, even by its most ardent supporters.”

    See the full article here.

    The American Association for the Advancement of Science is an international non-profit organization dedicated to advancing science for the benefit of all people.

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  • richardmitnick 7:15 pm on October 14, 2014 Permalink | Reply
    Tags: , Energy,   

    From ORNL: “New ORNL electric vehicle technology packs more punch in smaller package” 

    i1

    Oak Ridge National Laboratory

    Oct. 14, 2014
    Media Contact: Ron Walli
    Communications
    865.576.0226

    Using 3-D printing and novel semiconductors, researchers at the Department of Energy’s Oak Ridge National Laboratory have created a power inverter that could make electric vehicles lighter, more powerful and more efficient.

    At the core of this development is wide bandgap material made of silicon carbide with qualities superior to standard semiconductor materials. Power inverters convert direct current into the alternating current that powers the vehicle. The Oak Ridge inverter achieves much higher power density with a significant reduction in weight and volume.

    “Wide bandgap technology enables devices to perform more efficiently at a greater range of temperatures than conventional semiconductor materials,” said ORNL’s Madhu Chinthavali, who led the Power Electronics and Electric Machinery Group on this project. “This is especially useful in a power inverter, which is the heart of an electric vehicle.”

    Specific advantages of wide bandgap devices include: higher inherent reliability; higher overall efficiency; higher frequency operation; higher temperature capability and tolerance; lighter weight, enabling more compact systems; and higher power density.

    Additive manufacturing helped researchers explore complex geometries, increase power densities, and reduce weight and waste while building ORNL’s 30-kilowatt prototype inverter.

    thing
    ORNL’s 30-kilowatt power inverter offers greater reliability and power in a compact package.

    “With additive manufacturing, complexity is basically free, so any shape or grouping of shapes can be imagined and modeled for performance,” Chinthavali said. “We’re very excited about where we see this research headed.”

    Using additive manufacturing, researchers optimized the inverter’s heat sink, allowing for better heat transfer throughout the unit. This construction technique allowed them to place lower-temperature components close to the high-temperature devices, further reducing the electrical losses and reducing the volume and mass of the package.

    Another key to the success is a design that incorporates several small capacitors connected in parallel to ensure better cooling and lower cost compared to fewer, larger and more expensive “brick type” capacitors.

    The research group’s first prototype, a liquid-cooled all-silicon carbide traction drive inverter, features 50 percent printed parts. Initial evaluations confirmed an efficiency of nearly 99 percent, surpassing DOE’s power electronics target and setting the stage for building an inverter using entirely additive manufacturing techniques.

    Building on the success of this prototype, researchers are working on an inverter with an even greater percentage of 3-D printed parts that’s half the size of inverters in commercially available vehicles. Chinthavali, encouraged by the team’s results, envisions an inverter with four times the power density of their prototype.

    Others involved in this work, which was to be presented today at the Second Institute of Electrical and Electronics Engineers Workshop on Wide Bandgap Power Devices and Applications in Knoxville, were Curt Ayers, Steven Campbell, Randy Wiles and Burak Ozpineci.

    Research for this project was conducted at ORNL’s National Transportation Research Center and Manufacturing Demonstration Facility, DOE user facilities, with funding from DOE’s Office of Energy Efficiency and Renewable Energy.

    See the full article here.

    ORNL is managed by UT-Battelle for the Department of Energy’s Office of Science. DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time.

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  • richardmitnick 8:57 pm on October 3, 2014 Permalink | Reply
    Tags: , Energy, , ,   

    From MIT: “Crumpled graphene could provide an unconventional energy storage” 


    MIT News

    October 3, 2014
    David L. Chandler | MIT News Office

    Two-dimensional carbon “paper” can form stretchable supercapacitors to power flexible electronic devices.

    When someone crumples a sheet of paper, that usually means it’s about to be thrown away. But researchers have now found that crumpling a piece of graphene “paper” — a material formed by bonding together layers of the two-dimensional form of carbon — can actually yield new properties that could be useful for creating extremely stretchable supercapacitors to store energy for flexible electronic devices.

    temp
    To form the crumpled graphene, a sheet of polymer material is stretched in both dimensions, then graphene paper is bonded to it. When the polymer is released in one direction, the graphene forms pleats, as shown in the bottom left image, taken with a scanning electron microscope (SEM). Then, when released in the other direction, it forms a chaotic crumpled pattern (top left). At top right, an SEM image shows the material in a partially crumpled state. At bottom right, SEM image of a piece that has been crumpled and then flattened out. Image courtesy of the researchers

    The finding is reported in the journal Scientific Reports by MIT’s Xuanhe Zhao, an assistant professor of mechanical engineering and civil and environmental engineering, and four other authors. The new, flexible supercapacitors should be easy and inexpensive to fabricate, the team says.

    “Many people are exploring graphene paper: It’s a good candidate for making supercapacitors, because of its large surface area per mass,” Zhao says. Now, he says, the development of flexible electronic devices, such as wearable or implantable biomedical sensors or monitoring devices, will require flexible power-storage systems.

    Like batteries, supercapacitors can store electrical energy, but they primarily do so electrostatically, rather than chemically — meaning they can deliver their energy faster than batteries can. Now Zhao and his team have demonstrated that by crumpling a sheet of graphene paper into a chaotic mass of folds, they can make a supercapacitor that can easily be bent, folded, or stretched to as much as 800 percent of its original size. The team has made a simple supercapacitor using this method as a proof of principle.

    The material can be crumpled and flattened up to 1,000 times, the team has demonstrated, without a significant loss of performance. “The graphene paper is pretty robust,” Zhao says, “and we can achieve very large deformations over multiple cycles.” Graphene, a structure of pure carbon just one atom thick with its carbon atoms arranged in a hexagonal array, is one of the strongest materials known.

    To make the crumpled graphene paper, a sheet of the material was placed in a mechanical device that first compressed it in one direction, creating a series of parallel folds or pleats, and then in the other direction, leading to a chaotic, rumpled surface. When stretched, the material’s folds simply smooth themselves out.

    Forming a capacitor requires two conductive layers — in this case, two sheets of crumpled graphene paper — with an insulating layer in between, which in this demonstration was made from a hydrogel material. Like the crumpled graphene, the hydrogel is highly deformable and stretchable, so the three layers remain in contact even while being flexed and pulled.

    Though this initial demonstration was specifically to make a supercapacitor, the same crumpling technique could be applied to other uses, Zhao says. For example, the crumpled graphene material might be used as one electrode in a flexible battery, or could be used to make a stretchable sensor for specific chemical or biological molecules.

    “This work is really exciting and amazing to me,” says Dan Li, a professor of materials engineering at Monash University in Australia who was not involved in this research. He says the team “provides an extremely simple but highly effective concept to make stretchable electrodes for supercapacitors by controlled crumpling of multilayered graphene films.” While other groups have made flexible supercapacitors, he says, “Making supercapacitors stretchable has been a great challenge. This paper provides a very smart way to tackle this challenge, which I believe will bring wearable energy storage devices closer.”

    The research team also included Jianfeng Zang at Huazhong University of Science and Technology and Changyang Cao, Yaying Feng, and Jie Liu at Duke University. The work was supported by the Office of Naval Research, the National Science Foundation, and the National 1000 Talents Program of China.

    See the full article here.

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  • richardmitnick 4:29 pm on September 29, 2014 Permalink | Reply
    Tags: , , Energy, ,   

    From PPPL: “PPPL successfully tests system for mitigating instabilities called ‘ELMs’ “ 


    PPPL

    September 29, 2014
    John Greenwald

    PPPL has successfully tested a Laboratory-designed device to be used to diminish the size of instabilities known as “edge localized modes (ELMs)” on the DIII–D tokamak that General Atomics operates for the U.S. Department of Energy in San Diego. Such instabilities can damage the interior of fusion facilities.

    DIII-D
    DIII–D

    The PPPL device injects granular lithium particles into tokamak plasmas to increase the frequency of the ELMs. The method aims to make the ELMs smaller and reduce the amount of heat that strikes the divertor that exhausts heat in fusion facilities.

    The system could serve as a possible model for mitigating ELMs on ITER, the fusion facility under construction in France to demonstrate the feasibility of fusion energy.

    iter tok
    ITER Tokamak

    “ELMs are a big issue for ITER,” said Mickey Wade, director of the DIII-D national fusion program at General Atomics. Large-scale ELMs, he noted, could melt plasma-facing components inside the ITER tokamak.

    General Atomics plans to install the PPPL-designed device, developed by physicist Dennis Mansfield and engineer Lane Roquemore, on DIII-D this fall. Previous experiments using deuterium-injection rather than lithium-injection have demonstrated the ability to increase the ELMs frequency on DIII-D, the ASDEX-Upgrade in Germany and the Joint European Torus in the United Kingdom.

    jet
    Joint European Torus

    Researchers at DIII-D now want to see how the results for lithium-injection compare with those obtained in the deuterium experiments on the San Diego facility. “We want to put them side-by-side,” Wade said.

    PPPL-designed systems have proven successful in mitigating ELMs on the EAST tokamak in Hefei, China, and have been used on a facility operated by the Italian National Agency for New Technologies in Frascati, Italy. A system also is planned for PPPL’s National Spherical Torus Experiment (NSTX), the Laboratory’s major fusion experiment, which is undergoing a $94 million upgrade.

    PPPL NSTX
    PPPL NSTX

    PPPL used salt grain-sized plastic pellets as proxies for lithium granules in testing the system for DIII-D. The pellets fell through a pinhole-sized opening inside a dropper to a rotating high-speed propeller that projected them onto a target precisely as planned.

    Joining Mansfield and Roquemore for the tests were physicists Erik Gilson and Alessandro Bortolon, a former University of Tennessee researcher now at PPPL who will begin an assignment to the DIII-D tokamak at General Atomics this fall. Also participating were Rajesh Maingi, the head of research on edge physics and plasma-facing components at PPPL, and engineer Alexander Nagy, who is on assignment to DIII-D.

    See the full article here.

    Princeton Plasma Physics Laboratory is a U.S. Department of Energy national laboratory managed by Princeton University.

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  • richardmitnick 4:04 pm on September 29, 2014 Permalink | Reply
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    From LBL: “MaxBin: Automated Sorting Through Metagenomes” 

    Berkeley Logo

    Berkeley Lab

    September 29, 2014
    Lynn Yarris (510) 486-5375

    Microbes – the single-celled organisms that dominate every ecosystem on Earth – have an amazing ability to feed on plant biomass and convert it into other chemical products. Tapping into this talent has the potential to revolutionize energy, medicine, environmental remediation and many other fields. The success of this effort hinges in part on metagenomics, the emerging technology that enables researchers to read all the individual genomes of a sample microbial community at once. However, given that even a teaspoon of soil can contain billions of microbes, there is a great need to be able to cull the genomes of individual microbial species from a metagenomic sequence.

    Enter MaxBin, an automated software program for binning (sorting) the genomes of individual microbial species from metagenomic sequences. Developed at the U.S. Department of Energy (DOE)’s Joint BioEnergy Institute (JBEI), under the leadership of Steve Singer, who directs JBEI’s Microbial Communities Group, MaxBin facilitates the genomic analysis of uncultivated microbial populations that can hold the key to the production of new chemical materials, such as advanced biofuels or pharmaceutical drugs.

    cd
    MaxBin, an automated software program for binning the genomes of individual microbial species from metagenomic sequences, is available on-line through JBEI.

    “MaxBin automates the binning of assembled metagenomic scaffolds using an expectation-maximization algorithm after the assembly of metagenomic sequencing reads,” says Singer, a chemist who also holds an appointment with Berkeley Lab’s Earth Sciences Division. “Previous binning methods either required a significant amount of work by the user, or required a large number of samples for comparison. MaxBin requires only a single sample and is a push-button operation for users.”

    three
    JBEI researchers Yu-Wei Wu, Steve Singer and Danny Tang developed MaxBin to automatically recover individual genomes from metagenomes using an expectation-maximization algorithm. (Photo by Roy Kaltschmidt)

    The key to the success of MaxBin is its expectation-maximization algorithm, which was developed by Yu-Wei Wu, a post-doctoral researcher in Singer’s group. This algorithm enables the classification of metagenomic sequences into discrete bins that represent the genomes of individual microbial populations within a sample community.

    “Using our expectation-maximization algorithm, MaxBin combines information from tetranucleotide frequencies and scaffold coverage levels to organize metagenomic sequences into the individual bins, which are predicted from an initial identification of marker genes in assembled sequences,” Wu says.

    MaxBin was successfully tested on samples from the Human Microbiome Project and from green waste compost. In these tests, which were carried out by Yung-Tsu Tang, a student intern from the City College of San Francisco, MaxBin proved to be highly accurate in its ability to recover individual genomes from metagenomic datasets with variable sequencing coverages.

    “Applying MaxBin to an enriched cellulolytic consortia enabled us to identify a number of uncultivated cellulolytic bacteria, including a myxobacterium that possesses a remarkably reduced genome and expanded set of genes for biomass deconstruction compared to its closest sequenced relatives,” Singer says. “This demonstrates that the processes required for recovering genomes from metagenomic datasets can be applied to understanding biomass breakdown in the environment”.

    MaxBin is now being used at JBEI in its efforts to use microbes for the production of advanced biofuels – gasoline, diesel and jet fuel – from plant biomass. MaxBin is also available for downloading. To date, more than 150 researchers have accessed it.

    A paper describing MaxBin in detail has been published in the journal Microbiome. The paper is titled MaxBin: an automated binning method to recover individual genomes from metagenomes using an expectation-maximization algorithm. Co-authoring this paper in addition to Singer, Wu and Tang, were Susannah Tringe of the Joint Genome Institute, and Blake Simmons of JBEI.

    • See the full article here.

    A U.S. Department of Energy National Laboratory Operated by the University of California

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  • richardmitnick 1:59 pm on September 26, 2014 Permalink | Reply
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    From PNNL: “Off-shore Power Potential Floating in the Wind” 


    PNNL Lab

    September 2014
    Web Publishing Services

    Results
    : Two bright yellow buoys – each worth $1.3 million – are being deployed by Pacific Northwest National Laboratory in Washington State’s Sequim Bay. The massive, 20,000-pound buoys are decked out with the latest in meteorological and oceanographic equipment to enable more accurate predictions of the power-producing potential of winds that blow off U.S. shores. Starting in November, they will be commissioned for up to a year at two offshore wind demonstration projects: one near Coos Bay, Oregon, and another near Virginia Beach, Virginia.

    off
    PNNL staff conduct tests in Sequim Bay, Washington, while aboard one of two new research buoys being commissioned to more accurately predict offshore wind’s power-producing potential.

    “We know offshore winds are powerful, but these buoys will allow us to better understand exactly how strong they really are at the heights of wind turbines,” said PNNL atmospheric scientist Dr. William J. Shaw. “Data provided by the buoys will give us a much clearer picture of how much power can be generated at specific sites along the American coastline – and enable us to generate that clean, renewable power sooner.”

    Why It Matters: Offshore wind is a new frontier for U.S. renewable energy developers. There’s tremendous power-producing potential, but limited information is available about ocean-based wind resources. A recent report estimated the U.S. could power nearly 17 million homes by generating more than 54 gigawatts of offshore wind energy, but more information is needed.

    See the full article here.

    Pacific Northwest National Laboratory (PNNL) is one of the United States Department of Energy National Laboratories, managed by the Department of Energy’s Office of Science. The main campus of the laboratory is in Richland, Washington.

    PNNL scientists conduct basic and applied research and development to strengthen U.S. scientific foundations for fundamental research and innovation; prevent and counter acts of terrorism through applied research in information analysis, cyber security, and the nonproliferation of weapons of mass destruction; increase the U.S. energy capacity and reduce dependence on imported oil; and reduce the effects of human activity on the environment. PNNL has been operated by Battelle Memorial Institute since 1965.

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  • richardmitnick 8:14 pm on September 21, 2014 Permalink | Reply
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    From M.I.T.: “Magnetic fields make the excitons go ’round” 


    MIT News

    September 21, 2014
    David L. Chandler | MIT News Office

    A major limitation in the performance of solar cells happens within the photovoltaic material itself: When photons strike the molecules of a solar cell, they transfer their energy, producing quasi-particles called excitons — an energized state of molecules. That energized state can hop from one molecule to the next until it’s transferred to electrons in a wire, which can light up a bulb or turn a motor.

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    But as the excitons hop through the material, they are prone to getting stuck in minuscule defects, or traps — causing them to release their energy as wasted light.

    Now a team of researchers at MIT and Harvard University has found a way of rendering excitons immune to these traps, possibly improving photovoltaic devices’ efficiency. The work is described in a paper in the journal Nature Materials.

    Their approach is based on recent research on exotic electronic states known as topological insulators, in which the bulk of a material is an electrical insulator — that is, it does not allow electrons to move freely — while its surface is a good conductor.

    The MIT-Harvard team used this underlying principle, called topological protection, but applied it to excitons instead of electrons, explains lead author Joel Yuen, a postdoc in MIT’s Center for Excitonics, part of the Research Laboratory of Electronics. Topological protection, he says, “has been a very popular idea in the physics and materials communities in the last few years,” and has been successfully applied to both electronic and photonic materials.

    Moving on the surface

    Topological excitons would move only at the surface of a material, Yuen explains, with the direction of their motion determined by the direction of an applied magnetic field. In that respect, their behavior is similar to that of topological electrons or photons.

    In its theoretical analysis, the team studied the behavior of excitons in an organic material, a porphyrin thin film, and determined that their motion through the material would be immune to the kind of defects that tend to trap excitons in conventional solar cells.

    The choice of porphyrin for this analysis was based on the fact that it is a well-known and widely studied family of materials, says co-author Semion Saikin, a postdoc at Harvard and an affiliate of the Center for Excitonics. The next step, he says, will be to extend the analysis to other kinds of materials.

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    Structure of porphine, the simplest porphyrin

    While the work so far has been theoretical, experimentalists are eager to pursue the concept. Ultimately, this approach could lead to novel circuits that are similar to electronic devices but based on controlling the flow of excitons rather that electrons, Yuen says. “If there are ever excitonic circuits,” he says, “this could be the mechanism” that governs their functioning. But the likely first application of the work would be in creating solar cells that are less vulnerable to the trapping of excitons.

    Eric Bittner, a professor of chemistry at the University of Houston who was not associated with this work, says, “The work is interesting on both the fundamental and practical levels. On the fundamental side, it is intriguing that one may be able to create excitonic materials with topological properties. This opens a new avenue for both theoretical and experimental work. … On the practical side, the interesting properties of these materials and the fact that we’re talking about pretty simple starting components — porphyrin thin films — makes them novel materials for new devices.”

    The work received support from the U.S. Department of Energy and the Defense Threat Reduction Agency. Norman Yao, a graduate student at Harvard, was also a co-author.

    See the full article here.

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  • richardmitnick 7:53 pm on September 21, 2014 Permalink | Reply
    Tags: , , Energy,   

    From M.I.T.: “New formulation leads to improved liquid battery” 


    MIT News

    September 21, 2014
    David L. Chandler | MIT News Office

    Cheaper, longer-lasting materials could enable batteries that make wind and solar energy more competitive.

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    Researchers at MIT have improved a proposed liquid battery system that could enable renewable energy sources to compete with conventional power plants.

    Donald Sadoway and colleagues have already started a company to produce electrical-grid-scale liquid batteries, whose layers of molten material automatically separate due to their differing densities. But the new formula — published in the journal Nature by Sadoway, former postdocs Kangli Wang and Kai Jiang, and seven others — substitutes different metals for the molten layers used in a battery previously developed by the team.

    Sadoway, the John F. Elliott Professor of Materials Chemistry, says the new formula allows the battery to work at a temperature more than 200 degrees Celsius lower than the previous formulation. In addition to the lower operating temperature, which should simplify the battery’s design and extend its working life, the new formulation will be less expensive to make, he says.

    The battery uses two layers of molten metal, separated by a layer of molten salt that acts as the battery’s electrolyte (the layer that charged particles pass through as the battery is charged or discharged). Because each of the three materials has a different density, they naturally separate into layers, like oil floating on water.

    The original system, using magnesium for one of the battery’s electrodes and antimony for the other, required an operating temperature of 700 C. But with the new formulation, with one electrode made of lithium and the other a mixture of lead and antimony, the battery can operate at temperatures of 450 to 500 C.

    Extensive testing has shown that even after 10 years of daily charging and discharging, the system should retain about 85 percent of its initial efficiency — a key factor in making such a technology an attractive investment for electric utilities.

    Currently, the only widely used system for utility-scale storage of electricity is pumped hydro, in which water is pumped uphill to a storage reservoir when excess power is available, and then flows back down through a turbine to generate power when it is needed. Such systems can be used to match the intermittent production of power from irregular sources, such as wind and solar power, with variations in demand. Because of inevitable losses from the friction in pumps and turbines, such systems return about 70 percent of the power that is put into them (which is called the “round-trip efficiency”).

    Sadoway says his team’s new liquid-battery system can already deliver the same 70 percent efficiency, and with further refinements may be able to do better. And unlike pumped hydro systems — which are only feasible in locations with sufficient water and an available hillside — the liquid batteries could be built virtually anywhere, and at virtually any size. “The fact that we don’t need a mountain, and we don’t need lots of water, could give us a decisive advantage,” Sadoway says.

    The biggest surprise for the researchers was that the antimony-lead electrode performed so well. They found that while antimony could produce a high operating voltage, and lead gave a low melting point, a mixture of the two combined both advantages, with a voltage as high as antimony alone, and a melting point between that of the two constituents — contrary to expectations that lowering the melting point would come at the expense of also reducing the voltage.

    “We hoped [the characteristics of the two metals] would be nonlinear,” Sadoway says — that is, that the operating voltage would not end up halfway between that of the two individual metals. “They proved to be [nonlinear], but beyond our imagination. There was no decline in the voltage. That was a stunner for us.”

    Not only did that provide significantly improved materials for the group’s battery system, but it opens up whole new avenues of research, Sadoway says. Going forward, the team will continue to search for other combinations of metals that might provide even lower-temperature, lower-cost, and higher-performance systems. “Now we understand that liquid metals bond in ways that we didn’t understand before,” he says.

    With this fortuitous finding, Sadoway says, “Nature tapped us on the shoulder and said, ‘You know, there’s a better way!’” And because there has been little commercial interest in exploring the properties and potential uses of liquid metals and alloys of the type that are most attractive as electrodes for liquid metal batteries, he says, “I think there’s still room for major discoveries in this field.”

    Robert Metcalfe, professor of innovation at the University of Texas at Austin, who was not involved in this work, says, “The Internet gave us cheap and clean connectivity using many kinds of digital storage. Similarly, we will solve cheap and clean energy with many kinds of storage. Energy storage will absorb the increasing randomness of energy supply and demand, shaving peaks, increasing availability, improving efficiency, lowering costs.”

    Metcalfe adds that Sadoway’s approach to storage using liquid metals “is very promising.”

    The research was supported by the U.S. Department of Energy’s Advanced Research Projects Agency-Energy and by French energy company Total.

    See the full article here.

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  • richardmitnick 1:46 pm on August 26, 2014 Permalink | Reply
    Tags: , Energy, , , ,   

    From Berkeley Lab: “Competition for Graphene” 

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    Berkeley Lab

    August 26, 2014
    Lynn Yarris (510) 486-5375

    A new argument has just been added to the growing case for graphene being bumped off its pedestal as the next big thing in the high-tech world by the two-dimensional semiconductors known as MX2 materials. An international collaboration of researchers led by a scientist with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) has reported the first experimental observation of ultrafast charge transfer in photo-excited MX2 materials. The recorded charge transfer time clocked in at under 50 femtoseconds, comparable to the fastest times recorded for organic photovoltaics.

    “We’ve demonstrated, for the first time, efficient charge transfer in MX2 heterostructures through combined photoluminescence mapping and transient absorption measurements,” says Feng Wang, a condensed matter physicist with Berkeley Lab’s Materials Sciences Division and the University of California (UC) Berkeley’s Physics Department. “Having quantitatively determined charge transfer time to be less than 50 femtoseconds, our study suggests that MX2 heterostructures, with their remarkable electrical and optical properties and the rapid development of large-area synthesis, hold great promise for future photonic and optoelectronic applications.”

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    Feng Wang is a condensed matter physicist with Berkeley Lab’s Materials Sciences Division and UC Berkeley’s Physics Department. (Photo by Roy Kaltschmidt)

    Wang is the corresponding author of a paper in Nature Nanotechnology describing this research. The paper is titled Ultrafast charge transfer in atomically thin MoS2/WS2 heterostructures. Co-authors are Xiaoping Hong, Jonghwan Kim, Su-Fei Shi, Yu Zhang, Chenhao Jin, Yinghui Sun, Sefaattin Tongay, Junqiao Wu and Yanfeng Zhang.

    MX2 monolayers consist of a single layer of transition metal atoms, such as molybdenum (Mo) or tungsten (W), sandwiched between two layers of chalcogen atoms, such as sulfur (S). The resulting heterostructure is bound by the relatively weak intermolecular attraction known as the van der Waals force. These 2D semiconductors feature the same hexagonal “honeycombed” structure as graphene and superfast electrical conductance, but, unlike graphene, they have natural energy band-gaps. This facilitates their application in transistors and other electronic devices because, unlike graphene, their electrical conductance can be switched off.

    “Combining different MX2 layers together allows one to control their physical properties,” says Wang, who is also an investigator with the Kavli Energy NanoSciences Institute (Kavli-ENSI). “For example, the combination of MoS2 and WS2 forms a type-II semiconductor that enables fast charge separation. The separation of photoexcited electrons and holes is essential for driving an electrical current in a photodetector or solar cell.”

    In demonstrating the ultrafast charge separation capabilities of atomically thin samples of MoS2/WS2 heterostructures, Wang and his collaborators have opened up potentially rich new avenues, not only for photonics and optoelectronics, but also for photovoltaics.

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    Photoluminescence mapping of a MoS2/WS2 heterostructure with the color scale representing photoluminescence intensity shows strong quenching of the MoS2 photoluminescence. (Image courtesy of Feng Wang group)

    “MX2 semiconductors have extremely strong optical absorption properties and compared with organic photovoltaic materials, have a crystalline structure and better electrical transport properties,” Wang says. “Factor in a femtosecond charge transfer rate and MX2 semiconductors provide an ideal way to spatially separate electrons and holes for electrical collection and utilization.”

    Wang and his colleagues are studying the microscopic origins of charge transfer in MX2 heterostructures and the variation in charge transfer rates between different MX2 materials.

    “We’re also interested in controlling the charge transfer process with external electrical fields as a means of utilizing MX2 heterostructures in photovoltaic devices,” Wang says.

    This research was supported by an Early Career Research Award from the DOE Office of Science through UC Berkeley, and by funding agencies in China through the Peking University in Beijing.

    See the full article here.

    A U.S. Department of Energy National Laboratory Operated by the University of California

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