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DMD Blog
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ScienceDaily (Nov. 17, 2011) — Galaxies learned to "go green" early in the history of the universe, continuously recycling immense volumes of hydrogen gas and heavy elements to build successive generations of stars stretching over billions of years. This ongoing recycling keeps galaxies from emptying their "fuel tanks" and therefore stretches out their star-forming epoch to over 10 billion years. However, galaxies that ignite a rapid firestorm of star birth can blow away their remaining fuel, essentially turning off further star-birth activity.
This conclusion is based on a series of Hubble Space Telescope observations that flexed the special capabilities of its comparatively new Cosmic Origins Spectrograph (COS) to detect otherwise invisible mass in the halo of our Milky Way and a sample of more than 40 other galaxies. Data from large ground-based telescopes in Hawaii, Arizona, and Chile also contributed to the studies by measuring the properties of the galaxies.
This invisible mass is made up of normal matter -- hydrogen, helium, and heavier elements such as carbon, oxygen, nitrogen, and neon -- as opposed to dark matter that is an unknown exotic particle pervading space.
The results are being published in three papers in the November 18 issue of Science magazine. The leaders of the three studies are Nicolas Lehner of the University of Notre Dame in South Bend, Ind.; Jason Tumlinson of the Space Telescope Science Institute in Baltimore, Md.; and Todd Tripp of the University of Massachusetts at Amherst.
The Key Findings
The color and shape of a galaxy is largely controlled by gas flowing through an extended halo around it. All modern simulations of galaxy formation find that they cannot explain the observed properties of galaxies without modeling the complex accretion and "feedback" processes by which galaxies acquire gas and then later expel it after processing by stars. The three studies investigated different aspects of the gas-recycling phenomenon.
"Our results confirm a theoretical suspicion that galaxies expel and can recycle their gas, but they also present a fresh challenge to theoretical models to understand these gas flows and integrate them with the overall picture of galaxy formation," Tumlinson says.
The team used COS observations of distant stars to demonstrate that a large mass of clouds is falling through the giant corona halo of our Milky Way, fueling its ongoing star formation. These clouds of ionized hydrogen reside within 20,000 light-years of the Milky Way disk and contain enough material to make 100 million suns. Some of this gas is recycled material that is continually being replenished by star formation and the explosive energy of novae and supernovae, which kicks chemically enriched gas back into the halo; the remainder is gas being accreted for the first time. The infalling gas from this vast reservoir fuels the Milky Way with the equivalent of about a solar mass per year, which is comparable to the rate at which our galaxy makes stars. At this rate the Milky Way will continue making stars for another billion years by recycling gas into the halo and back onto the galaxy. "We now know where is the missing fuel for galactic star formation," Lehner concludes. "We now have to find out its birthplace."
One goal of the studies was to study how other galaxies like our Milky Way accrete mass for star making. But instead of widespread accretion, the team found nearly ubiquitous halos of hot gas surrounding vigorous star-forming galaxies. These galaxy halos, rich in heavy elements, extend as much as 450,000 light-years beyond the visible portions of their galactic disks. The surprise was discovering how much mass in heavy elements is far outside a galaxy. COS measured 10 million solar masses of oxygen in a galaxy's halo, which corresponds to about 1 billion solar masses of gas -- as much as in the entire interstellar medium between stars in a galaxy's disk. They also found that this gas is nearly absent from galaxies that have stopped forming stars. This is evidence that widespread outflows, rather than accretion, determine a galaxy's fate. "We didn't know how much mass was there in these gas halos, because we couldn't do these observations until we had COS," Tumlinson says. "This stuff is a huge component of galaxies but can't be seen in any images."
He points out that because so much of the heavy elements has been ejected into the halos instead of sticking around in the galaxies, the formation of planets, life, and other things requiring heavy elements could have been delayed in these galaxies.
The COS data also demonstrate that those galaxies forming stars at a very rapid rate, perhaps a hundred solar masses per year, can drive 2-million-degree gas very far out into intergalactic space at speeds of up to 2 million miles per hour. That's fast enough for the gas to escape forever and never refuel the parent galaxy. While hot plasma "winds" from galaxies have been known for some time, the new COS observations reveal that hot outflows extend to much greater distances than previously thought and can carry a tremendous amount of mass out of a galaxy. Some of the hot gas is moving more slowly and could eventually be recycled. The Hubble observations show how gas-rich star-forming spiral galaxies can evolve to quiescent elliptical galaxies that no longer have star formation. "So not only have we found that star-forming galaxies are pervasively surrounded by large halos of hot gas," says Tripp, "we have also observed that hot gas in transit -- we have caught the stuff in the process of moving out of a galaxy and into intergalactic space."
The light emitted by this hot plasma is invisible, so the researchers used COS to detect the presence of the gas by the way it absorbs certain colors of light from background quasars. The brightest objects in the universe, quasars are the brilliant cores of active galaxies that contain rapidly accreting supermassive black holes. The quasars serve as distant lighthouse beacons that shine through the gas-rich "fog" of hot plasma encircling galaxies. At ultraviolet wavelengths, COS is sensitive to absorption from many ionized heavy elements, such as nitrogen, oxygen, and neon. COS's high sensitivity allows many galaxies that happen to lie in front of the much more distant quasars to be studied. The ionized heavy elements serve as proxies for estimating how much mass is in a galaxy's halo.
"Only with COS can we now address some of the most crucial questions that are at the forefront of extragalactic astrophysics," Tumlinson says. Source: http://www.nasa.gov/mission_pages/hubble/science/recyclers.html
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The Electronics TakeBack Coalition, which promotes responsible e-recycling, says 50 to 80 percent of electronics recycled in the United States are shipped overseas. Barbara Kyle, the TakeBack Coalition's executive director, estimates that much of this is sent to developing countries. Asian countries like China and Vietnam as well as African countries like Ghana and Nigeria receive the bulk of the waste, Kyle said.
Developing nations like these have few or no regulations, Kyle said, and as a result, a whole industry based on crude, unsafe methods to extract the minerals exists. Many contain toxic materials that harm surrounding environments and populations, Kyle said.
"If they can pull the metals out by bashing and burning, that's what they do," Kyle said. "These are people working for a few dollars a day and don't get health safety."
Perhaps the biggest problem about this is that most of the exporting is legal in the United States. The only regulation that Kyle could point to is an EPA rule requiring exporters to notify the agency before sending out cathode ray tubes, such as the ones contained in many older television sets.
If the exporter claims that the tubes are for reuse, then it just needs to give EPA a one-time notice, regardless of the laws of the country they're being shipped to, Kyle said. There's also no limit to how much e-waste an exporter can ship overseas.
John Shegerian is chairman and CEO of Electronic Recyclers International, one of the world's largest electronic waste recyclers. Shegerian attributes the problem to a culture within the industry that's pressured to find the cheapest recycling options. "What you've got is well-meaning people choosing the lowest-costing scenario," Shegerian said. "This goes for corporations as well as the federal government."
His mantra is that responsible recycling isn't cheap.
The TakeBack Coalition and many others, including major companies like Dell and Samsung, are backing legislation that would ban shipping e-waste to Third World countries. In September, Reps. Gene Green (D-Texas) and Mike Thompson (D-Calif.) introduced the "Responsible Electronics Recycling Act," which would have made such practices illegal. Because it was introduced late in the session, the bill didn't get any hearings and quickly died. It will likely be reintroduced this session, Kyle said.
In the meantime, e-recyclers can volunteer for certifications like e-Stewards, a program developed to prevent misuse of toxics in the electronics, especially in Third World countries. More than 50 recyclers are certified or in the process of doing so.
Article Courtesy of: JOEY PETERS of ClimateWire
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Each year, new electronics hit the market and capture consumers' attention, giving them reason to throw away the old VCR or standard television and engross themselves in state-of-the-art gadgetry. Most of the time, the old electronics end up in the garbage, despite holding plenty of reusable material. But a push for recycling them has gained ground in recent years through both new state laws and a developing "e-recycling" industry.
Imagine a fleet of miners flocking to landfills and disassembling the dated electronics for their batteries and power supplies. John Shegerian uses the term "urban mining" to describe this process. Shegerian is chairman and CEO of Electronic Recyclers International, one of the world's largest electronic waste recyclers. To him, urban mining is a budding global industry that encompasses essentially anything that's recyclable. "Urban mining goes way beyond electronics," he said. "It's everything that goes into a landfill that can be taken out."
But electronics are a mainstay for companies like ERI, especially since many contain "precious metals" like platinum, iridium and others that could have large implications for energy independence and renewable energy in the United States. Many of the most valuable metals are mined outside U.S. borders and are used in everyday electronic materials. China alone accounts for 97 percent of the rare earth metal market.
E-recycling has been prompted both by organizations like ERI and state laws seeking to prevent "e-waste," or electronics that end up in landfills. California was first to pass e-waste legislation in 2003. The state has processed nearly 1 billion pounds of e-waste since then and has 60 recyclers and 600 collectors.
Twenty-four other states have since followed suit, mostly in the past few years, but California's law stands out because it charges a consumer fee on certain electronics. The fee goes on covered electronic devices, or any electronic item with a screen bigger than 4 inches. Buying a big-screen TV, for instance, may require a $10 fee that gets diverted into a recycling fund. The fund goes back to recyclers and collectors, who are paid a subsidy based on the amount of electronics they bring to a recycling plant. Collectors typically get about 30 cents per pound of e-waste.
Two state agencies oversee the e-waste law: CalRecycle, which is in charge of the fee and payment system, and the state Department of Toxic Substances Control, which visits recycling plants to monitor the storage of toxic materials.
Other states with e-waste laws take "producer responsibility" approaches, which seek to shift the burden of recycling costs from the taxpayers back to the manufacturers. Manufacturers are pushed to make products that can be easily recycled or made from recyclable materials. The catch is, they have to pay for it themselves.
The laws and regulations help the e-recycling industry thrive. ERI alone has seven recycling plants nationwide and processes more than 120 million pounds of e-waste a year.
But despite e-recycling's growth, most old electronics in the United States still end up in the trash. U.S. EPA estimates that in 2009, more than 82 percent of discarded electronics went to landfills and incinerators. The Electronics TakeBack Coalition, which promotes responsible e-recycling, says 50 to 80 percent of electronics recycled in the United States are shipped overseas. Shegerian said that estimate may even be conservative.
Article Courtesy of: JOEY PETERS of ClimateWire
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The Basis for the Environmental Benefits of Refurbished IT
The scientific basis for the environmental case for refurbished IT equipment is primarily from Dr. Eric Williams of Rochester Institute of Technology in his book, co-authored with Ruediger Kuehr, Computers and the Environment, Understanding and Managing Their Impacts.
In it, they find that the environmental cost to produce a computer and monitor is immense, especially for microprocessors. Producing the average 53-pound desktop computer and CRT monitor requires 530 pounds of fossil fuels, 50 pounds of chemicals, and 3,330 pounds of water.
Adding additional life to computers saves 5 to 20 times more energy than recycling over the computer's life cycle. It's much better for the environment to extend the life of a computer for an extra two or three years than to buy a new one every three to four years.
The thing I found perhaps most interesting in the Williams and Kuehr findings is that 75 percent of PC energy consumption has already happened before a new computer is ever switched on. It is used up in the production phase. If this equipment has a six or seven year lifespan rather than three or four years, the environmental impact of this for even a fraction of the one billion plus computers now in use in the world will be immense.
Half the Periodic Table in That PC or Mobile Phone
The green argument for electronics reuse goes beyond Williams and Kuehr, however. Paul Hawkin, in his book, Natural Capitalism, finds that the volume of material that goes into manufacturing a laptop is 4,000 to 1. When you discard a 5 pound laptop you are also throwing away the 20,000 pounds of raw materials it took to make it.
The hundreds of raw materials that are needed to make electronics devices have an incredibly long and complex supply chain. They must come from mines and factories from all over the world. The University of Illinois Sustainable Electronics Initiative estimates that each PC or mobile phone contains about half the periodic table.
How Much Does Reuse Save?
The EPA's Electronics Environmental Benefits Calculator shows environmental savings for computer recycling and reuse in terms of energy, materials, CO2, toxic emissions, and more. It finds that it is roughly 25 times more beneficial environmentally to reuse computers than to recycle them at 3 to 5 years of age.
Recent lifecycle assessment work by Eric Munsing of PE International has found that in more energy efficient devices like laptops, tablets and mobile phones, the environmental benefit of extending the useful life of these devices only increases. More energy and resources are expended in their manufacturing phase.
How Does Refurbished Equipment Stack Up?
The environmental case for electronics reuse aside, one question that always crops up is how refurbished IT equipment compares with new equipment in terms of performance. Most of us have been frustrated by using a three or four year old computer that takes forever to start up and do simple things like open a web page or send an email message. The main reason for this is that over time, software degrades or corrupts, developing interoperability conflicts and many other glitches.
A machine that is repaired, cleaned out, and has fresh software installed that is native to it pretty much runs as well as the day it was new. One important thing to know is that a four-year-old computer needs software that runs well on four-year-old equipment, and not the latest software versions.
The Bottom Line
The bottom line is that most people do four or five things on computers: email, internet browsing, accounting, multimedia (video and music), and office applications like word processing. Three or four year old equipment does all of that easily.
Article Courtesy of Jim Lynch- Techsoup
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Computerworld - The IT shop at JM Family Enterprises has taken the typical steps to make its data centers eco-friendly: It has consolidated systems, virtualized servers and set up hot and cold aisles to drive down energy consumption.
Such initiatives have enabled the widely diversified Deerfield Beach, Fla.-based automotive services company to eliminate more than 1,400 physical servers and avoid using more than 5.5 million kilowatt-hours of electricity annually over the past several years.
But IT leaders thought they could do more, so they invested in alternative energy, installing a solar energy array at the company's Alpharetta, Ga., data center. The array is capable of supporting 100% of the data center's power requirements and eliminating an annual release of 205 metric tons of carbon dioxide.
The switch to solar is one of many sustainability initiatives that the company's IT unit has undertaken.
Vice President and CTO Shawn Berg says IT has been actively involved in such projects since 2006, when it first started to virtualize data center servers.
"We've always focused on community and the environment; they were core issues for us," Berg says.
Virtualization, which has been an ongoing, multiyear effort, was IT's initial step toward a more formal, systematic approach to sustainability that the company adopted in 2008, Berg says.
In addition to virtualizing servers, the IT department has adhered to a rigid equipment refresh cycle to ensure that the company uses the latest, most energy-efficient systems. And the Georgia data center, built in 2009, has many green features in addition to its solar array.
Now the IT department is focused on adopting green efforts in other areas, Berg says.
This year, JM Family started a virtual desktop project under which IT aims to eventually provide all employees with virtual desktops. This will help cut down on the amount of e-waste the company generates and reduce energy consumption. JM Family estimates that the thin clients will use 80% less energy than traditional PCs.
IT also helped implement a print reduction initiative this year, Berg says. The goal is to cut paper consumption by 12,000 pounds per year.
And in an effort to further reduce its impact on the environment, Berg says, JM Family is looking at the possibility of sharing data center space with other companies.
Article By Mary K. Pratt- ComputerWorld
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