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New Process Uses Concentrated Solar Heat to Vaporize Biomass
Yale Environment 360 - 5 hours 35 min ago
A U.S. startup has developed a process that uses concentrated solar heat to vaporize biomass into synthetic fuels, a system the company says is cleaner and more efficient and can produce twice as much fuel per ton of biomass as existing systems. In the process, a network of solar mirrors direct sunlight at a mounted gasifying unit, heating ceramic tubes to 1,200 to 1,300 degrees C. Any biomass, such as wood and crop waste, that is passed through the tubes becomes vaporized and is converted into synthetic gas, the company says. At such extreme temperatures, the process leaves behind little tar residue, which the developers say can be expensive to get rid of and can kill the catalysts that reform the product into liquid fuel later in the process. And unlike other gasification processes — in which the heating comes from the burning of 30 to 35 percent of the biomass — this system requires no biomass to heat the unit, said Alan Weimer, a chemical engineering professor at the University of Colorado, Boulder, who is working with Colorado-based Sundrop Fuels to commercialize the process.
Categories: Environmental News
Study Tracks 'Outsourcing' of Greenhouse Gas Emissions
Yale Environment 360 - 6 hours 6 min ago
More than one-third of the carbon dioxide emissions associated with consumer goods used in developed nations is actually emitted in other nations where the products are made, according to a new study. In the U.S., about 2.5 tons of carbon produced per person annually — or about 11 percent of U.S. per capita emissions — are emitted elsewhere, researchers at the Carnegie Institution for Science say. In Europe, it’s about four tons of carbon per person. In fact, in smaller European nations like Switzerland, the emissions associated with products manufactured outside the borders exceed the actual emissions produced at home. Using 2004 trade data from 113 countries and regions, the authors of the study, published in the Proceedings of the National Academy of Sciences, were able to
Steven Davis/Carnegie Institution for Science'Outsourcing' Carbon Emissions construct a global model of the flow of “imported” and “exported” emissions, most of which are “outsourced” to developing nations. The biggest “importer” by far is China, they said. “Just like the electricity that you use in your home probably causes CO2 emissions at a coal-burning power plant somewhere else, we found that the products imported by the developed countries of western Europe, Japan, and the United States cause substantial emissions in other countries, especially China,” said lead author Steven Davis.Categories: Environmental News
Scientists Develop New Plastics That Can Be Recycled Continuously
Yale Environment 360 - Tue, 03/09/2010 - 11:21
Researchers at IBM and Stanford University say they have found a way to produce plastics that can be recycled continuously or used as higher-value products such as for the pharmaceutical industry. By using organic catalysts in the production of plastic polymers, rather than metal catalysts, the scientists say it is possible to produce a new class of plastics that will not degrade as quickly when recycled, according to a paper published in the journal Macromolecules. “If you use organic reactants, you can make certain types of new polymers that are quite different and have other properties plastics don’t have,” said Chandrasekhar Narayan, who leads the IBM science and technology team in San Jose, Calif. Researchers say these plastics can replace those that are difficult to recycle, such as polyethylene terephthatlate (PET), which is used in common products such as plastic beverage bottles. Currently, the 13 billion plastic bottles tossed away annually in the U.S. can not be reused as bottles, and are difficult to recycle. Narayan predicted that bottles using the new plastics could be recycled for use as automobile parts and that the new plastics could also be used to deliver drugs to treat cancer.
Categories: Environmental News
Earthquake Shifted Cities As Far As Ten Feet, Researchers Say
Yale Environment 360 - Tue, 03/09/2010 - 09:56
The 8.8 magnitude earthquake that struck Chile last month moved the city of Concepcion, the city closest to the quake’s epicenter, 10 feet to the west and shifted cities across the continent, according to an analysis of global positioning satellite (GPS) data. Santiago, Chile’s capital city, moved nearly a foot, and Buenos Aires, the Argentinean capital located on the other side of the continent, shifted about an inch, say researchers at Ohio State University, one of four universities and several agencies that have been studying the measurements since the Feb. 27 quake. Valparaiso, Chile, shifted 11 inches to the west and and Mendoza, Argentina, moved
University of HawaiiSeismic effects of Feb. 27 earthquake 3.5 inches in the same direction, said Michael Bevis, a professor of earth sciences at Ohio State who has measured crustal motion and deformation in the central and southern Andes since 1993. The massive quake occurred when the Nazca tectonic plate was subducted beneath the adjacent South American plate. Researchers compared GPS locations known prior to the quake with those recorded 10 days later. According to the U.S. Geological Survey, dozens of aftershocks have occurred in the days since the initial quake, some exceeding a magnitude of 6.0.Categories: Environmental News
Record Wind Generation Tests Texas's Transmission System
Yale Environment 360 - Mon, 03/08/2010 - 10:59
Wind power generation in Texas is growing so quickly that it is testing the limits of the state’s electrical grid. The state set a record on March 5 when wind turbines generated 6,272 megawatts of energy, or about 19 percent of the electricity on the state’s main power grid. That peak far exceeded the 6.2 percent average for wind power in Texas, whose 9,410 megawatts of total wind capacity make it the nation’s wind power leader. But wind power’s growth poses a critical challenge for the state’s booming wind industry, which includes a 180-megawatt wind farm completed last fall near Corpus Christi in South Texas. On some days wind turbines are slowed or shut down because the state doesn’t have enough transmission wires to send the energy from remote areas, where wind resources are great, to cities that need it, including Dallas and Houston. The state is planning to spend more than $5 billion to expand and update its transmission system.
Categories: Environmental News
New Combustion System Greatly Boosts Gas Mileage, Company Says
Yale Environment 360 - Mon, 03/08/2010 - 10:36
A California-based startup company claims it has developed an improved version of the internal combustion engine that boosts gas mileage by more than 50 percent and enabled a prototype vehicle to get 64 miles per gallon on the highway in recent test drives. Transonic Combustion, backed by Vinod Khosla and other venture capitalists, says it has invented a new fuel injection system that heats and pressurizes gasoline before injecting it into the combustion chamber, placing the fuel in a “supercritical” state that allows for clean and fast combustion. Once the fuel is injected into the piston, the heat and pressure enable the fuel to combust Transonic CombustionTransonic Combustion’s new fuel-injection technology without a spark. Ignition also can be timed to occur just when the piston reaches its optimal point, further improving fuel efficiency. Transonic said that it plans to build its first factory in 2013 and begin producing cars in 2014. One key question is what impact the increased temperature and pressure of the gasoline will have on the life expectancy of an engine. William Green, a professor of chemical engineering at the Massachusetts Institute of Technology, said Transonic’s new engine is one of many being developed to significantly boost the fuel efficiency of engines. “It’s a time of renaissance for internal combustion engines,” said Green.
Categories: Environmental News
World’s Pall of Black Carbon Can Be Eased With New Stoves
Yale Environment 360 - Mon, 03/08/2010 - 07:30
Two billion people worldwide do their cooking on open fires, producing sooty pollution that shortens millions of lives and exacerbates global warming. If widely adopted, a new generation of inexpensive, durable cook stoves could go a long way toward alleviating this problem. BY JON R. LUOMA
Categories: Environmental News
New Methane Releases Discovered in Siberian Arctic, Study Says
Yale Environment 360 - Fri, 03/05/2010 - 10:24
Methane, a gas with at least 25 times the heat-trapping power of carbon dioxide, is leaking through a layer of thawing, sub-sea permafrost that has long acted as a barrier over a reservoir of methane in the East Siberian Arctic, according to a new study. Further destabilization of the permafrost barrier on the Arctic shelf “could trigger abrupt climate warming,” scientists at the University of Alaska Fairbanks International Arctic Research Center said. Sizable methane leaks have recently been discovered in other Arctic regions, and the University of Alaska researchers took air and water measurements of methane at 5,000 sites from 2003 to 2008 along the East Siberian Arctic Shelf. The scientists say that roughly 7 to 11 million tons of methane are now leaking through the shelf in East Siberia annually, a small amount compared to man-made carbon-dioxide levels released worldwide. Levels of methane in the atmosphere above the Arctic have reached 1.85 parts per million, nearly three times the global average, and methane levels in East Siberia are 2 parts per million or more, said Natalia Shakhova, a researcher at the University of Fairbanks and lead author of the study, which was published in the journal Science. “Our concern is that the sub-sea has been showing signs of destabilization already,” Shakhova told reporters. “It if further destabilizes, the methane emissions... would be significantly larger.” The methane was formed by the decay of plant matter that accumulated in the soil of the Arctic shelf when it was peatland above sea level.
Categories: Environmental News
New Methane Releases Discovered in Siberian Arctic, Study Says
Yale Environment 360 - Fri, 03/05/2010 - 10:24
Methane, a gas with at least 25 times the heat-trapping power of carbon dioxide, is leaking through a layer of thawing, sub-sea permafrost that has long acted as a barrier over a reservoir of methane in the East Siberian Arctic, according to a new study. Further destabilization of the permafrost barrier on the Arctic shelf “could trigger abrupt climate warming,” scientists at the University of Alaska Fairbanks International Arctic Research Center said. Sizable methane leaks have recently been discovered in other Arctic regions, and the University of Alaska researchers took air and water measurements of methane at 5,000 sites from 2003 to 2008 along the East Siberian Arctic Shelf. The scientists say that roughly 7 to 11 million tons of methane are now leaking through the shelf in East Siberia annually, a small amount compared to man-made carbon-dioxide levels released worldwide. Levels of methane in the atmosphere above the Arctic have reached 1.85 parts per million, nearly three times the global average, and methane levels in East Siberia are 2 parts per million or more, said Natalia Shakhova, a researcher at the University of Fairbanks and lead author of the study, which was published in the journal Science. “Our concern is that the sub-sea has been showing signs of destabilization already,” Shakhova told reporters. “It if further destabilizes, the methane emissions... would be significantly larger.” The methane was formed by the decay of plant matter that accumulated in the soil of the Arctic shelf when it was peatland above sea level.
Categories: Environmental News
New Methane Releases Discovered in Siberian Arctic, Study Says
Yale Environment 360 - Fri, 03/05/2010 - 10:24
Methane, a gas with at least 25 times the heat-trapping power of carbon dioxide, is leaking through a layer of thawing, sub-sea permafrost that has long acted as a barrier over a reservoir of methane in the East Siberian Arctic, according to a new study. Further destabilization of the permafrost barrier on the Arctic shelf “could trigger abrupt climate warming,” scientists at the University of Alaska Fairbanks International Arctic Research Center said. Sizable methane leaks have recently been discovered in other Arctic regions, and the University of Alaska researchers took air and water measurements of methane at 5,000 sites from 2003 to 2008 along the East Siberian Arctic Shelf. The scientists say that roughly 7 to 11 million tons of methane are now leaking through the shelf in East Siberia annually, a small amount compared to man-made carbon-dioxide levels released worldwide. Levels of methane in the atmosphere above the Arctic have reached 1.85 parts per million, nearly three times the global average, and methane levels in East Siberia are 2 parts per million or more, said Natalia Shakhova, a researcher at the University of Fairbanks and lead author of the study, which was published in the journal Science. “Our concern is that the sub-sea has been showing signs of destabilization already,” Shakhova told reporters. “It if further destabilizes, the methane emissions... would be significantly larger.” The methane was formed by the decay of plant matter that accumulated in the soil of the Arctic shelf when it was peatland above sea level.
Categories: Environmental News
New Online System Maps Risks to Forests in U.S. South
Yale Environment 360 - Thu, 03/04/2010 - 11:30
The World Resources Institute has launched a website that maps forests in the southern United States, which produce more pulp for paper than any place on Earth. Using satellite imagery, GoogleEarth technology, and decades of forest data, the site — SeeSouthernForests.org — depicts threats to the region’s forests including pest and pathogen outbreaks, wildfire, logging, and human development, the leading cause of deforestation in the South. About 27 percent of forests in the region are owned by companies and financial institutions, while individuals and families still
NASADeforestation and urbanization of Atlanta, Georgia own about 60 percent. “Surveys indicate that most families want to pass their forests on to the next generation,” said Todd Gartner, manager of Conservation Incentives at the American Forest Foundation. “However, with increasing development pressure, market-based incentives are needed to ensure that private forests remain as forests.” WRI officials hope the new online resource will illustrate the history of these forests, and help landowners better understand how numerous forces are affecting the region.Categories: Environmental News
‘Buy America’ Provision Sought For Clean Energy Projects in Stimulus Plan
Yale Environment 360 - Thu, 03/04/2010 - 09:41
Four Democratic U.S. senators have asked the Obama administration to stop investment in wind power and other renewable energy projects until the government ensures that the projects primarily use U.S. labor and materials. The senators, led by U.S. Sen. Charles E. Schumer, introduced legislation requiring that economic stimulus funds only be spent on clean-energy projects that use materials made in the U.S. and that create a majority of jobs in America. The four senators also asked Treasury Secretary Timothy F. Geithner to apply the so-called “Buy America” provision to all future energy projects funded under the Obama administration’s economic stimulus program. The senators are attempting to require “Buy America” provisions after learning that 75 percent of the $2 billion spent on wind energy projects supported by the stimulus program reportedly went to foreign companies. Schumer said that a $1.5 billion West Texas wind project using Chinese-built turbines would create 3,000 jobs in China and only 300 in the United States. But the American Wind Energy Association, a trade group, harshly criticized the senators’ actions, saying that invoking the “Buy America” provision would “torpedo one of the most successful job creation efforts of the Recovery Act” by driving away foreign investment in U.S. wind farms.
Categories: Environmental News
‘Buy America’ Provision Sought For Clean Energy Projects in Stimulus Plan
Yale Environment 360 - Thu, 03/04/2010 - 09:41
Four Democratic U.S. senators have asked the Obama administration to stop investment in wind power and other renewable energy projects until the government ensures that the projects primarily use U.S. labor and materials. The senators, led by U.S. Sen. Charles E. Schumer, introduced legislation requiring that economic stimulus funds only be spent on clean-energy projects that use materials made in the U.S. and that create a majority of jobs in America. The four senators also asked Treasury Secretary Timothy F. Geithner to apply the so-called “Buy America” provision to all future energy projects funded under the Obama administration’s economic stimulus program. The senators are attempting to require “Buy America” provisions after learning that 75 percent of the $2 billion spent on wind energy projects supported by the stimulus program reportedly went to foreign companies. Schumer said that a $1.5 billion West Texas wind project using Chinese-built turbines would create 3,000 jobs in China and only 300 in the United States. But the American Wind Energy Association, a trade group, harshly criticized the senators’ actions, saying that invoking the “Buy America” provision would “torpedo one of the most successful job creation efforts of the Recovery Act” by driving away foreign investment in U.S. wind farms.
Categories: Environmental News
After Two Decades of Delay, A Chance to Save Bluefin Tuna
Yale Environment 360 - Thu, 03/04/2010 - 07:34
Normal.dotm 0 0 1 43 246 Yale University 2 1 302 12.1 0 false 18 pt 18 pt 0 0 false false false /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-ascii-font-family:Cambria; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Cambria; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} The obscenely profitable market for bluefin tuna in Japan has led to years of overfishing and left the world’s bluefin population badly depleted. A ban on the bluefin trade, if adopted at international talks this month, would go a long way toward giving this magnificent fish a chance to recover. BY CARL SAFINA
Categories: Environmental News
After Two Decades of Delay, A Chance to Save Bluefin Tuna
Yale Environment 360 - Thu, 03/04/2010 - 07:34
Normal.dotm 0 0 1 43 246 Yale University 2 1 302 12.1 0 false 18 pt 18 pt 0 0 false false false /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-ascii-font-family:Cambria; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Cambria; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} The obscenely profitable market for bluefin tuna in Japan has led to years of overfishing and left the world’s bluefin population badly depleted. A ban on the bluefin trade, if adopted at international talks this month, would go a long way toward giving this magnificent fish a chance to recover. BY CARL SAFINA
Categories: Environmental News
Quantum computers
Nature - Thu, 03/04/2010 - 06:00
Quantum computers
Nature 464, 45 (2010). doi:10.1038/nature08812
Authors: T. D. Ladd, F. Jelezko, R. Laflamme, Y. Nakamura, C. Monroe & J. L. O’Brien
Over the past several decades, quantum information science has emerged to seek answers to the question: can we gain some advantage by storing, transmitting and processing information encoded in systems that exhibit unique quantum properties? Today it is understood that the answer is yes, and many research groups around the world are working towards the highly ambitious technological goal of building a quantum computer, which would dramatically improve computational power for particular tasks. A number of physical systems, spanning much of modern physics, are being developed for quantum computation. However, it remains unclear which technology, if any, will ultimately prove successful. Here we describe the latest developments for each of the leading approaches and explain the major challenges for the future.
Categories: Literature
A human gut microbial gene catalogue established by metagenomic sequencing
Nature - Thu, 03/04/2010 - 06:00
A human gut microbial gene catalogue established by metagenomic sequencing
Nature 464, 59 (2010). doi:10.1038/nature08821
Authors: Junjie Qin, Ruiqiang Li, Jeroen Raes, Manimozhiyan Arumugam, Kristoffer Solvsten Burgdorf, Chaysavanh Manichanh, Trine Nielsen, Nicolas Pons, Florence Levenez, Takuji Yamada, Daniel R. Mende, Junhua Li, Junming Xu, Shaochuan Li, Dongfang Li, Jianjun Cao, Bo Wang, Huiqing Liang, Huisong Zheng, Yinlong Xie, Julien Tap, Patricia Lepage, Marcelo Bertalan, Jean-Michel Batto, Torben Hansen, Denis Le Paslier, Allan Linneberg, H. Bjørn Nielsen, Eric Pelletier, Pierre Renault, Thomas Sicheritz-Ponten, Keith Turner, Hongmei Zhu, Chang Yu, Shengting Li, Min Jian, Yan Zhou, Yingrui Li, Xiuqing Zhang, Songgang Li, Nan Qin, Huanming Yang, Jian Wang, Søren Brunak, Joel Doré, Francisco Guarner, Karsten Kristiansen, Oluf Pedersen, Julian Parkhill, Jean Weissenbach, Peer Bork, S. Dusko Ehrlich & Jun Wang
To understand the impact of gut microbes on human health and well-being it is crucial to assess their genetic potential. Here we describe the Illumina-based metagenomic sequencing, assembly and characterization of 3.3 million non-redundant microbial genes, derived from 576.7 gigabases of sequence, from faecal samples
Categories: Literature
Linking dwarf galaxies to halo building blocks with the most metal-poor star in Sculptor
Nature - Thu, 03/04/2010 - 06:00
Linking dwarf galaxies to halo building blocks with the most metal-poor star in Sculptor
Nature 464, 72 (2010). doi:10.1038/nature08772
Authors: Anna Frebel, Evan N. Kirby & Joshua D. Simon
Current cosmological models indicate that the Milky Way’s stellar halo was assembled from many smaller systems. On the basis of the apparent absence of the most metal-poor stars in present-day dwarf galaxies, recent studies claimed that the true Galactic building blocks must have been vastly different from the surviving dwarfs. The discovery of an extremely iron-poor star (S1020549) in the Sculptor dwarf galaxy based on a medium-resolution spectrum cast some doubt on this conclusion. Verification of the iron-deficiency, however, and measurements of additional elements, such as the α-element Mg, are necessary to demonstrate that the same type of stars produced the metals found in dwarf galaxies and the Galactic halo. Only then can dwarf galaxy stars be conclusively linked to early stellar halo assembly. Here we report high-resolution spectroscopic abundances for 11 elements in S1020549, confirming its iron abundance of less than 1/4,000th that of the Sun, and showing that the overall abundance pattern follows that seen in low-metallicity halo stars, including the α-elements. Such chemical similarity indicates that the systems destroyed to form the halo billions of years ago were not fundamentally different from the progenitors of present-day dwarfs, and suggests that the early chemical enrichment of all galaxies may be nearly identical.
Categories: Literature
Superconductivity in alkali-metal-doped picene
Nature - Thu, 03/04/2010 - 06:00
Superconductivity in alkali-metal-doped picene
Nature 464, 76 (2010). doi:10.1038/nature08859
Authors: Ryoji Mitsuhashi, Yuta Suzuki, Yusuke Yamanari, Hiroki Mitamura, Takashi Kambe, Naoshi Ikeda, Hideki Okamoto, Akihiko Fujiwara, Minoru Yamaji, Naoko Kawasaki, Yutaka Maniwa & Yoshihiro Kubozono
Efforts to identify and develop new superconducting materials continue apace, motivated by both fundamental science and the prospects for application. For example, several new superconducting material systems have been developed in the recent past, including calcium-intercalated graphite compounds, boron-doped diamond and—most prominently—iron arsenides such as LaO1–xFxFeAs (ref. 3). In the case of organic superconductors, however, no new material system with a high superconducting transition temperature (Tc) has been discovered in the past decade. Here we report that intercalating an alkali metal into picene, a wide-bandgap semiconducting solid hydrocarbon, produces metallic behaviour and superconductivity. Solid potassium-intercalated picene (Kxpicene) shows Tc values of 7 K and 18 K, depending on the metal content. The drop of magnetization in Kxpicene solids at the transition temperature is sharp (<2 K), similar to the behaviour of Ca-intercalated graphite. The Tc of 18 K is comparable to that of K-intercalated C60 (ref. 4). This discovery of superconductivity in Kxpicene shows that organic hydrocarbons are promising candidates for improved Tc values.
Categories: Literature
Reinventing germanium avalanche photodetector for nanophotonic on-chip optical interconnects
Nature - Thu, 03/04/2010 - 06:00
Reinventing germanium avalanche photodetector for nanophotonic on-chip optical interconnects
Nature 464, 80 (2010). doi:10.1038/nature08813
Authors: Solomon Assefa, Fengnian Xia & Yurii A. Vlasov
Integration of optical communication circuits directly into high-performance microprocessor chips can enable extremely powerful computer systems. A germanium photodetector that can be monolithically integrated with silicon transistor technology is viewed as a key element in connecting chip components with infrared optical signals. Such a device should have the capability to detect very-low-power optical signals at very high speed. Although germanium avalanche photodetectors (APD) using charge amplification close to avalanche breakdown can achieve high gain and thus detect low-power optical signals, they are universally considered to suffer from an intolerably high amplification noise characteristic of germanium. High gain with low excess noise has been demonstrated using a germanium layer only for detection of light signals, with amplification taking place in a separate silicon layer. However, the relatively thick semiconductor layers that are required in such structures limit APD speeds to about 10 GHz, and require excessively high bias voltages of around 25 V (ref. 12). Here we show how nanophotonic and nanoelectronic engineering aimed at shaping optical and electrical fields on the nanometre scale within a germanium amplification layer can overcome the otherwise intrinsically poor noise characteristics, achieving a dramatic reduction of amplification noise by over 70 per cent. By generating strongly non-uniform electric fields, the region of impact ionization in germanium is reduced to just 30 nm, allowing the device to benefit from the noise reduction effects that arise at these small distances. Furthermore, the smallness of the APDs means that a bias voltage of only 1.5 V is required to achieve an avalanche gain of over 10 dB with operational speeds exceeding 30 GHz. Monolithic integration of such a device into computer chips might enable applications beyond computer optical interconnects—in telecommunications, secure quantum key distribution, and subthreshold ultralow-power transistors.
Categories: Literature