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Thursday, January 16, 2014

5,900 natural gas leaks discovered under Washington, D.C.

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5,900 natural gas leaks discovered under Washington, D.C.
This is a map of the District of Columbia showing where researchers found natural gas leaks under city streets, with colors indicating the concentration in parts per million of methane at each location. Credit: Duke University

More than 5,893 leaks from aging natural gas pipelines have been found under the streets of Washington, D.C. by a research team from Duke University and Boston University.
 A dozen of the leaks could have posed explosion risks, the researchers said. Some manholes had concentrations as high as 500,000 parts per million of natural gas – about 10 times greater than the threshold at which explosions can occur.

Four months after phoning in the leaks to city authorities, the research team returned and found that nine were still emitting dangerous levels of methane. "Finding the leaks a second time, four months after we first reported them, was really surprising," said Robert B. Jackson, a professor of environmental sciences at Duke who led the study.

The researchers published their findings this week in the peer-reviewed journal Environmental Science & Technology.

"Repairing these leaks will improve air quality, increase consumer health and safety, and save money," Jackson said. "Pipeline safety has been improving over the last two decades. Now is the time to make it even better."

Nationally, natural gas failures cause an average of 17 fatalities, 68 injuries, and $133 million in property damage annually, according to the U.S. Pipeline and Hazardous Materials Safety Administration.

In addition to the explosion hazard, natural gas leaks also pose another threat: Methane, the primary ingredient of natural gas, is a powerful greenhouse gas that also can catalyze ozone formation. Pipeline leaks are the largest human-caused source of methane in the United States and contribute to $3 billion of lost and unaccounted for natural gas each year.
5,900 natural gas leaks discovered under Washington, D.C.
This is a satellite image of the District of Colombia with bar charts showing where natural gas leaks were located under city streets and in what concentration methane was identified. Higher bars indicate higher concentrations in parts per million. Credit: Duke University

Jackson's team collaborated with researchers from Boston University and Gas Safety, Inc., on the new study. The team mapped gas leaks under all 1,500 road miles within Washington using a high-precision Picarro G2301 Cavity Ring-Down Spectrometer installed in a GPS-equipped car. Laboratory analyses then confirmed that the isotopic chemical signatures of the methane and ethane found in the survey closely matched that of pipeline gas.

The average methane concentration observed in the leaks was about 2.5 times higher than in background air samples collected in the city. Methane levels in some leaks were as high as 89 parts per million, about 45 times higher than normal background levels.

The team also measured how much methane was coming from four individual street-level leaks. "Methane emissions from these four leaks ranged from 9,200 to 38,200 liters per day for each leak—that's comparable to the amount of natural gas used by between 2 and 7 homes," said Duke Ph.D. student Adrian Down.

Last year, the team mapped more than 3,300 leaks beneath 785 road miles in the city of Boston. "The average density of leaks we mapped in the two cities is comparable, but the average methane concentrations are higher in Washington," said Nathan G. Phillips, a professor at Boston University's Department of Earth and Environment.

Like Washington and Boston, many U.S. cities have aging pipeline infrastructure that may be prone to leaks. The researchers recommend coordinated gas-leak mapping campaigns in cities where the infrastructure is deemed to be at risk.

The new study comes at a time when the nation's aging pipeline infrastructure is generating increased legislative attention. Last November, Sen. Edward J. Markey (D-Mass.) introduced two new bills to speed up the replacement of pipelines in states with older infrastructures by offering new federal programs and incentives to help defray the costs associated with the repairs.

"We need to put the right financial incentives in place," said Jackson. "Companies and public utility commissions need help to fix leaks and replace old cast iron pipes more quickly."
Explore further: Developing a new laser to detect methane leaks      

More information: "Natural Gas Pipeline Leaks Across Washington, D.C.," Robert B. Jackson, Adrian Down, Nathan G. Phillips, Robert C. Ackley, Charles W. Cook, Desiree L. Plata and Kaiguang Zhao. Environmental Science & Technology, January 16, 2014. dx.doi.org/10.1021/es404474x
Journal reference: Environmental Science & Technology

 Read more at: http://phys.org/news/2014-01-natural-gas-leaks-washington-dc.html#jCp

Chasing the Dream of Half-Price Gasoline from Natural Gas

A startup called Siluria thinks it’s solved a mystery that has stymied huge oil companies for decades.  By Kevin Bullis on January 15, 2014

http://www.technologyreview.com/news/523146/chasing-the-dream-of-half-price-gasoline-from-natural-gas/?utm_campaign=socialsync&utm_medium=social-post&utm_source=facebook            
 
 
At a pilot plant in Menlo Park, California, a technician pours white pellets into a steel tube and then taps it with a wrench to make sure they settle together. He closes the tube, and oxygen and methane—the main ingredient of natural gas—flow in. Seconds later, water and ethylene, the world’s largest commodity chemical, flow out. Another simple step converts the ethylene into gasoline.
The white pellets are a catalyst developed by the Silicon Valley startup Siluria, which has raised $63.5 million in venture capital. If the catalysts work as well in a large, commercial scale plant as they do in tests, Siluria says, the company could produce gasoline from natural gas at about half the cost of making it from crude oil—at least at today’s cheap natural-gas prices.
If Siluria really can make cheap gasoline from natural gas it will have achieved something that has eluded the world’s top chemists and oil and gas companies for decades. Indeed, finding an inexpensive and direct way to upgrade natural gas into more valuable and useful chemicals and fuels could finally mean a cheap replacement for petroleum.

Natural gas burns much more cleanly than oil—power plants that burn oil emit 50 percent more carbon dioxide than natural gas ones. It also is between two and six times more abundant than oil, and its price has fallen dramatically now that technologies like fracking and horizontal drilling have led to a surge of production from unconventional sources like the Marcellus Shale. While oil costs around $100 a barrel, natural gas sells in the U.S. for the equivalent of $20 a barrel.

But until now oil has maintained a crucial advantage: natural gas is much more difficult to convert into chemicals such as those used to make plastics. And it is relatively expensive to convert natural gas into liquid fuels such as gasoline. It cost Shell $19 billion to build a massive gas-to-liquids plant in Qatar, where natural gas is almost free. The South African energy and chemicals company Sasol is considering a gas-to-liquids plant in Louisiana that it says will cost between $11 billion and $14 billion. Altogether, such plants produce only about 400,000 barrels of liquid fuels and chemicals a day, which is less than half of 1 percent of the 90 million barrels of oil produced daily around the world.

The costs are so high largely because the process is complex and consumes a lot of energy. First high temperatures are required to break methane down into carbon monoxide and hydrogen, creating what is called syngas. The syngas is then subjected to catalytic reactions that turn it into a mixture of hydrocarbons that is costly to refine and separate into products.
For years, chemists have been searching for catalysts that would simplify the process, skipping the syngas step and instead converting methane directly into a specific, desired chemical. Such a process wouldn’t require costly refining and separation steps, and it might consume less energy. But the chemistry is difficult—so much so that some of the world’s top petroleum companies gave up on the idea in the 1980s.

Siluria thinks it can succeed where others have failed not because it understands the chemistry better, but because it has developed new tools for making and screening potential catalysts. Traditionally, chemists have developed catalysts by analyzing how they work and calculating what combination of elements might improve them. Siluria’s basic philosophy is to try out a huge number of catalysts in the hope of getting lucky. The company built an automated system—it looks like a mess of steel and plastic tubes, mass spectrometers, small stainless steel furnaces, and data cables—that can quickly synthesize hundreds of different catalysts at a time and then test how well they convert methane into ethylene.

The system works by varying both what catalysts are made of—the combinations and ratios of various elements—and their microscopic structure. Siluria was founded based on the work of Angela Belcher, a professor of biological engineering at MIT who developed viruses that can assemble atoms of inorganic materials into precise shapes. Siluria uses this and other methods to form nanowires from the materials that make up its catalysts. Sometimes the shape of a nanowire changes the way the catalyst interacts with gases such as methane—and this can transform a useless combination of elements into an effective one. “How you build up the structure of the catalyst matters as much as its composition,” says Erik Scher, Siluria’s vice president of research and development.
The process of making and testing catalysts isn’t completely random—Siluria has the work of earlier chemists to guide it, and it has developed software that sorts out the most efficient way to screen a wide variety of possibilities. The result is that what used to take chemists a year Siluria can now do in a couple of days, Scher says. “We’ve made and screened over 50,000 catalysts at last count,” he says. “And I haven’t been counting in a while.”

Nonetheless, some seasoned chemists are skeptical that Siluria can succeed. Siluria’s process is a version of one that chemists pursued in the 1970s and 1980s known as oxidative coupling, which involves reacting methane with oxygen. The problem with this approach is that it’s hard to get the reaction to stop at ethylene and not keep going to make carbon dioxide and water. “The reaction conditions you need to convert methane to ethylene do at least as good a job, if not better, of converting ethylene into carbon dioxide, which is useless,” says Jay Labinger, a chemist at the Beckman Institute at Caltech.

In the late 1980s, Labinger wrote a paper that warned researchers not to waste their time working on the process. And history seems to have borne him out. The process “hasn’t been, and doesn’t appear at all likely to be” an economically viable one, he says.

Yet in spite of the challenging chemistry, Siluria says the performance of its catalysts at its pilot plant have justified building two larger demonstration plants—one across San Francisco Bay in Hayward, California, that will make gasoline, and one in Houston that will only make ethylene. The plants are designed to prove to investors that the technology can work at a commercial scale, and that the process can be plugged into existing refineries and chemical plants, keeping down capital costs. The company hopes to open its first commercial plants within four years.
The hope for finding more valuable uses for natural gas—and making natural gas a large-scale alternative to oil—doesn’t rest on Siluria alone. The abundance of cheap natural gas has fueled a number of startups with other approaches. Given the challenges that such efforts have faced, there’s good reason to be skeptical that they will succeed, says David Victor, director of the Laboratory on International Law and Regulation at the University of California at San Diego. But should some of them break through, he says, “that would be seismic.”

Wednesday, January 15, 2014

Strange Metal Asteroid Targeted in Far-Out NASA Mission Concept


By Mike Wall, Senior Writer   |   January 15, 2
014 07:49am ET 
 
   
Proposed Mission to Metal Asteroid Psyche
Artist's concept of a spacecraft studying the huge metal asteroid Psyche from orbit.
Credit: JPL/Corby Waste
 

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Mike Wall

Michael was a science writer for the Idaho National Laboratory and has been an intern at Wired.com, The Salinas Californian newspaper, and the SLAC National Accelerator Laboratory. He has also worked as a herpetologist and wildlife biologist. He has a Ph.D. in evolutionary biology from the University of Sydney, Australia, a bachelor's degree from the University of Arizona, and a graduate certificate in science writing from the University of California, Santa Cruz. To find out what his latest project is, you can follow Mike on .
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Contact @michaeldwall on Twitter Contact Mike Wall by EMail
 


- See more at: http://www.space.com/24288-strange-metal-asteroid-psyche-nasa-mission.html?cmpid=556375#sthash.RNnvcLhp.dpuf

Sunday, January 12, 2014

Seriously, how susceptible are we to this today?

Flashback Friday: the mysterious dancing epidemic of 1518. - Seriously, Science? | DiscoverMagazine.com

Flashback Friday: the mysterious dancing epidemic of 1518.

By Seriously Science | January 10, 2014 7:00 am
Figure 1: Half bird's-eye view of Strasbourg by Franz Hogenberg, contained in Georg Braun and Hogenberg's Civitates Orbis Terrarum published in 1572.
Figure 1: Half bird’s-eye view of Strasbourg by Franz Hogenberg, contained in Georg Braun and Hogenberg’s Civitates Orbis Terrarum published in 1572.

In their free time, some scientists and doctors like to try to figure out causes of medically-related historical events. For example, the authors of this study investigate what may have caused the crazy dancing “epidemic” of 1518 in Strasbourg: “Some time in mid-July 1518 a lone woman stepped into one of its narrow streets and began a dancing vigil that was to last four or even 6 days in succession. Within a week another 34 had joined the dance. And by the end of August, one chronicler asserts, 400 people had experienced the madness, dancing wildly, uncontrollably around the city.” And this wasn’t a sedate affair; the dancers’ feet often ended up bruised and bloody. The authors were not able assign a biological cause to the epidemic (it seems unlikely that hallucinogenic compounds from the rye fungus ergot were involved), but they suggest that hunger and psychological stress were the likely culprit, with a healthy dose of religious belief thrown in: “In times of acute hardship, with physical and mental distress leaving people more than usually suggestible, a fear of St Vitus could rapidly take hold. All it then took was for one or a few emotionally frail people, believing themselves to have been cursed by St.Vitus, to slip into a trance. Then they would unconsciously act out the part of those who had incurred his wrath: dancing wildly, uncontrollably for days on end.” The description of the events, and the government’s (likely unhelpful) response, is fascinating. We have included our favorite bits from the full text below. Enjoy!

In a spin: the mysterious dancing epidemic of 1518.
“In 1518, one of the strangest epidemics in recorded history struck the city of Strasbourg. Hundreds of people were seized by an irresistible urge to dance, hop and leap into the air. In houses, halls and public spaces, as fear paralyzed the city and the members of the elite despaired, the dancing continued with mindless intensity. Seldom pausing to eat, drink or rest, many of them danced for days or even weeks. And before long, the chronicles agree, dozens were dying from exhaustion. What was it that could have impelled as many as 400 people to dance, in some cases to death?”

“As the dance turned epidemic, troubled nobles and burghers consulted local physicians. Having excluded astrological and supernatural causes, the members of the medical fraternity declared it to be a ‘natural disease’ caused by ‘hot blood’ 2, 4 and 5. This was orthodox physic, consistent with Galen’s view that bloody fluxes could overheat the brain, causing anger, rashness and madness. But the response of the authorities was neither to bleed nor to provide cooling diets. Instead they prescribed ‘more dancing’. To this end they cleared two guildhalls and the outdoor grain market and they even had a wooden stage constructed opposite the horse fair. To these locations the dancers were taken so they could dance freely and uninterrupted. The victims would only recover their minds, said the authorities, if they persisted both day and night with their frantic movements. And to facilitate this supposed cure, the authorities next paid for musicians and professional dancers to keep the afflicted moving.

Every time the sick flagged, fainted, stumbled or slowed, the musicians raised the tempo of their playing and hired dancers held them firm and quickened their pace (Figure 2). ‘They danced day and night with those poor people’, one eye-witness recalled 1, 2 and 4. In grain market and horse fair, the elites had created spectacles every bit as grotesque as a Hieronymous Bosch canvas portraying human folly or the torments of Hell.

Only after those with weak hearts or prone to strokes began to die did the governors rethink their strategy. Deciding that the dance had nothing to do with putrefying blood cooking normally moist and cool brains, they now saw it as a curse sent down by an angry saint. Hence, a period of organised contrition was instituted: gambling, gaming and prostitution were banned and the dissolute driven beyond the city gates. Soon after the dancers were despatched to a mountaintop shrine in the Vosges mountains to pray for divine intercession. There they were led around an altar, wearing red shoes provided for the ceremony, upon which stood a bas-relief carving of St. Vitus, the Virgin and Pope Marcellus. In the following weeks the epidemic abated. Most of the dancers, we are told, regained bodily control…”

Saturday, January 11, 2014

Black hole's 'big meal' could spark fireworks


If the black hole "bites" the gas cloud, X-ray "fireworks" will flare out

Astronomers are getting ready for their best ever glimpse of the mysterious black hole at the heart of our galaxy.

"Fireworks" will flare if it gobbles up a giant gas cloud which is drifting perilously close.

A collision is now likely in spring, according to scientists at the American Astronomical Society meeting.

Stargazers will be able to see the climax on a new public monitoring website.

"This could be our black hole's biggest meal in hundreds of years," said Leo Meyer, of the University of California, Los Angeles.  "It might bring spectacular fireworks - and we want everybody to watch."

The collision could give astronomers a unique window on one of the universe's great enigmas.  Black holes are so dense that not even light can escape them, once it passes their event horizon (point of no return).

The heart of our Milky Way galaxy - a seven-year-long X-ray by Swift.
The heart of our Milky Way galaxy - a seven-year-long X-ray by Swift. The black hole is hidden in the centre

They can only be observed indirectly - from brief flashes of radiation released by matter falling in.

The giant gas cloud G2 is three times the mass of Earth. It was first spotted in 2011 hurtling towards Sagittarius A* - the black hole in our galactic core.  Impact is now just a few months away. If the gas drifts close enough it will heat up, releasing great flares of X-rays, which shed light on the black hole's properties.

Astronomers have already secured front row seats. Dr Meyer's team is tracking the cloud's approach using the Keck Observatory in Hawaii.

They can see it "stretching like spaghetti" as the black hole tugs at its head, now moving much faster than its tail.

A gas cloud being 'stretched like spaghetti' by the black hole's gravity
The gas cloud is being 'stretched like spaghetti' by the black hole's gravity

And while Keck watches the cloud, Swift is watching the black hole. Nasa's X-Ray space telescope is poised and primed to catch the first glimmers of an encounter.

"Everyone wants to see the event happening because it's so rare," said Nathalie Degenaar, Swift's principal investigator.

Sagittarius A* lurks 26,000 light years away in the Milky Way's innermost region.  Viewed from Earth, it is in the southern summer sky near the constellations Sagittarius and Scorpius.

Black holes

Artist's impression, supermassive black hole
  • Black holes are incredibly dense objects with gravity strong enough to trap even light
  • A 'medium' black hole could have the mass of 1,000 Suns but be no bigger than Earth
  • Supermassive black holes are thought to be at the centre of most large galaxies - including ours
Source: BBC Science

Even for a black hole it is dim - about a billion times fainter than others of its "supermassive" type.
And this makes it something of a mystery.

"Currently it's not easy to see at all. But if the gas cloud suddenly feeds it with much more mass, you might get fireworks. And with that, you can test all sorts of theories," said Dr Meyer.

Black holes are thought to play a crucial role in the life cycles of galaxies.  They eat matter from their surroundings and blow matter back. This influences how stars are formed, how the galaxy grows, and how it interacts with other galaxies.

To get a sense of the typical feeding habits of Sagittarius A*, the Swift team has been making regular observations since 2006.  Every few days, their spacecraft turns toward the galaxy's core and takes a 17-minute-long exposure.  To date, they have detected six strong flares where the black hole was 150 times brighter for a couple of hours. But these are mere flickers compared to the jets that could erupt from G2 - the display could last for years.  Exactly how dramatic it transpires to be depends on what's inside the cloud.

If it is mostly hydrogen gas, the X-rays will glow for years to come as the black hole slowly swallows it.

The cloud was spotted in 2011 hurtling towards the galactic core
The cloud was spotted in 2011 hurtling towards the galactic core

But there is another possibility - the cloud could be hiding an old star. In which case, the big dinner date could be an anticlimax.

The black hole may slurp a little from the cloud while the star slips on by at a safe distance, dense enough to escape its gravity.

"I would be delighted if Sagittarius A* suddenly became 10,000 times brighter. However it's possible it will not react much - like a horse that won't drink when led to water," said Jon Miller, of the University of Michigan.

"Will there be fireworks or not? We have to wait and see. There is no smoking gun that can tell us yet," said Dr Meyer.

"But even if the odds are against it, you still have to look, because if you do see something it could be spectacular."

Thursday, January 9, 2014

Global Climate Change | Source of NASA Data

For more information, go to Global Climate Change | MY NASA DATA.  Below is only part of the introduction to the source.

Global Climate Change:  An Excellent Source of NASA Data


Welcome to the Global Climate Change data visualization tool on MY NASA DATA. This page links you to a powerful data viewer that will allow you to examine all of the key climate change indicators that have been identified on the Global Climate Change website. You will be able to view these indicators on the Live Access Server (LAS) that we’ve configured for you to view global and local data pertaining to these key areas of interest. CO2 AIRS sample

For all of the parameters below, after clicking on their respective links, please click on “Choose Dataset” button on the upper left hand side of the LAS page and then click on the cross directly to the left of the indicator that you’d like to view, for some browsers, the Choose Dataset dialogue box will automatically appear. We’ve provided a description of each parameter that is currently available. If you have and questions or issues with the LAS please email the MY NASA DATA support team.

Algorithmic information theory

From Wikipedia, the free encyclopedia https://en.wikipedia.org/wiki/Algorithmic_information_theory ...