Researchers find that some 'green' hot water systems fail to deliver on promises

Public release date: 2-May-2013
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Contact: Steven Mackay
smackay@vt.edu
540-231-4787
Virginia Tech

Two researchers affiliated with the Virginia Tech College of Engineering have published a paper which reports that hot water recirculating systems touted as "green," actually use both more energy and water than their standard counterparts.

Marc Edwards, the Charles P. Lunsford Professor of Civil and Environmental Engineering in the Virginia Tech College of Engineering, originated the efficiency study of the systems as part of an undergraduate design class six years ago. After a thorough analysis, the class concluded the claims as false, and that it "was thermodynamically impossible for these systems to save energy as claimed," said Edwards.

The topic was selected as part of a dissertation by Randi Brazeau during her doctorate in Virginia Tech's Charles E. Via Jr. Department of Civil and Environmental Engineering. The results are presented in a paper published in the most recent issue of Journal of Green Building.

Brazeau, now an assistant professor of environmental science at Metropolitan State University of Denver, examined the energy and water savings of continuous hot water recirculating systems in a comparative, direct test versus traditional hot water systems in which consumers often wait for the cold water to flush down the drain before the water warms to a comfortable temperature for showering.

She found that the recirculation systems used 20 percent more energy even in the best possible scenario in which the water pump was only on for a few seconds before use, and in scenarios where the pump was always on, the recirculation systems could require more than double the energy to operate. The consumer pays for this extra energy in higher electric and fuel bills.

"Randi demonstrated that when all energy costs are accounted for, including that necessary to run the pump, the hot water recirculating systems always used much more energy than the conventional systems," said Edwards.

A previous U.S. Department of Energy report and certain manufacturers claimed the recirculation devices would not only eliminate wait times, but also would save both water and energy. It also was assumed that because consumers did not need to wait for water to warm, the hot water recirculation systems would at minimum save water from being wasted. But that claim did not consider that it takes water to make energy, said Edwards.

The research found that the "so-called green" hot water recirculation systems used more net water than the conventional systems after accounting for water needed to produce the extra energy. "These are really consumer comfort and convenience devices, a luxury really, masquerading as 'green' or environmentally conscious devices," Edwards said.

Other findings: On-demand electric systems operate with nearly 100 percent energy efficiency, but cannot be used in many circumstances dependent on scaling and incoming water temperature, and may require expensive upgrades to home electrical systems and use of low or ultra-low flow showerheads.

In many cases, hot water recirculating systems touted as "green" are not just a consumer choice, but required in some new homes and businesses in the United States, said Brazeau. But their energy savings, and therefore lessened environmental impact claimed by manufacturers "do not hold water," she added.

Brazeau and Edwards calculated that a typical consumer with an electric water heater would pay as much as $158 more annually compared to systems without recirculation. More research, though, is necessary to better inform policy and decision-making by regulators, public health officials, manufacturers, and consumers, Edwards and Brazeau said.

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Public release date: 2-May-2013
[ | E-mail | Share ]

Contact: Steven Mackay
smackay@vt.edu
540-231-4787
Virginia Tech

Two researchers affiliated with the Virginia Tech College of Engineering have published a paper which reports that hot water recirculating systems touted as "green," actually use both more energy and water than their standard counterparts.

Marc Edwards, the Charles P. Lunsford Professor of Civil and Environmental Engineering in the Virginia Tech College of Engineering, originated the efficiency study of the systems as part of an undergraduate design class six years ago. After a thorough analysis, the class concluded the claims as false, and that it "was thermodynamically impossible for these systems to save energy as claimed," said Edwards.

The topic was selected as part of a dissertation by Randi Brazeau during her doctorate in Virginia Tech's Charles E. Via Jr. Department of Civil and Environmental Engineering. The results are presented in a paper published in the most recent issue of Journal of Green Building.

Brazeau, now an assistant professor of environmental science at Metropolitan State University of Denver, examined the energy and water savings of continuous hot water recirculating systems in a comparative, direct test versus traditional hot water systems in which consumers often wait for the cold water to flush down the drain before the water warms to a comfortable temperature for showering.

She found that the recirculation systems used 20 percent more energy even in the best possible scenario in which the water pump was only on for a few seconds before use, and in scenarios where the pump was always on, the recirculation systems could require more than double the energy to operate. The consumer pays for this extra energy in higher electric and fuel bills.

"Randi demonstrated that when all energy costs are accounted for, including that necessary to run the pump, the hot water recirculating systems always used much more energy than the conventional systems," said Edwards.

A previous U.S. Department of Energy report and certain manufacturers claimed the recirculation devices would not only eliminate wait times, but also would save both water and energy. It also was assumed that because consumers did not need to wait for water to warm, the hot water recirculation systems would at minimum save water from being wasted. But that claim did not consider that it takes water to make energy, said Edwards.

The research found that the "so-called green" hot water recirculation systems used more net water than the conventional systems after accounting for water needed to produce the extra energy. "These are really consumer comfort and convenience devices, a luxury really, masquerading as 'green' or environmentally conscious devices," Edwards said.

Other findings: On-demand electric systems operate with nearly 100 percent energy efficiency, but cannot be used in many circumstances dependent on scaling and incoming water temperature, and may require expensive upgrades to home electrical systems and use of low or ultra-low flow showerheads.

In many cases, hot water recirculating systems touted as "green" are not just a consumer choice, but required in some new homes and businesses in the United States, said Brazeau. But their energy savings, and therefore lessened environmental impact claimed by manufacturers "do not hold water," she added.

Brazeau and Edwards calculated that a typical consumer with an electric water heater would pay as much as $158 more annually compared to systems without recirculation. More research, though, is necessary to better inform policy and decision-making by regulators, public health officials, manufacturers, and consumers, Edwards and Brazeau said.

###

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AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.

Source: http://www.eurekalert.org/pub_releases/2013-05/vt-rft050213.php

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Shaking things up: Researchers propose new old way to purify carbon nanotubes

May 1, 2013 ? An old, somewhat pass?, trick used to purify protein samples based on their affinity for water has found new fans at the National Institute of Standards and Technology (NIST), where materials scientists are using it to divvy up solutions of carbon nanotubes, separating the metallic nanotubes from semiconductors. They say it's a fast, easy and cheap way to produce high-purity samples of carbon nanotubes for use in nanoscale electronics and many other applications.

Carbon nanotubes are formed from rolled-up sheets of carbon atoms arranged in a hexagonal pattern resembling chicken wire. One of the amazing features of nanotubes is that, depending on just how the sheet rolls up, a quality called chirality, the resulting tube can behave either like a semiconductor, with various properties, or like a metal, with electrical conductance up to 10 times better than copper. One big issue in creating commercially viable electronics based on nanotubes is being able to efficiently sort out the kind you want.

Thinking about how to do this, says NIST researcher Constantine Khripin, brought up the subject of biochemists and so-called "two-phase liquid extraction." "Biologists used this to separate proteins, even viruses," says Khripin, "It's an old technique, it was popular in the 70s, but then HPLC [high-performance liquid chromatography] replaced a lot of those techniques." People use HPLC to partition carbon nanotubes as well, he says, but it's less successful. HPLC divides things by exploiting differences in the mobility of the desired molecules as they travel small columns loaded with tiny spheres, but carbon nanotubes tend to stick to the spheres, reducing yield and eventually clogging the equipment.

The concept of liquid extraction is relatively straightforward. You make a mixture in water of two polymers that you've selected to be just slightly different in their "hydrophobicity," or tendency to mix with water. Add in your sample of stuff to be separated, stir vigorously and wait. The polymer solutions will gradually separate into two distinct portions or "phases," the lighter one on top. And they'll bring along with them those molecules in your sample that share a similar degree of hydrophobicity.

It turns out that this works pretty well with nanotubes because of differences in their electronic structure -- the semiconductor forms, for example, are more hydrophobic than the metallic forms. It's not perfect, of course, but a few sequential separations ends up with a sample where the undesired forms are essentially undetectable.

Be honest. It's not that easy. "No," agrees, Khripin, "People tried this before and it didn't work. The breakthrough was to realize that you need a very subtle difference between the two phases. The difference in hydrophobity between nanotubes is tiny, tiny, tiny." But you can engineer that with careful addition of salts and surfactants.

"This technique uses some vials and a bench-top centrifuge worth a couple hundred dollars, and it takes under a minute," observes team member Jeffrey Fagan. "The other techniques people use require an HPLC on the order of $50,000 and the yields are relatively low, or an ultracentrifuge that takes 12 to 20 hours to separate out the different metals from semiconductors, and it's tricky and cumbersome."

"The nanotube metrology project at NIST has been around for a quite a number of years," says senior team member Ming Zheng. "It has been a constant interest of ours to develop new ways to separate nanotubes, cheaper ways, that industry can use in the development of nanoelectronics and other applications. We really think we have a method here that fits all the criteria that people are looking for. It's easy, it's scalable, it's high resolution -- all the good attributes put together."

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The above story is reprinted from materials provided by National Institute of Standards and Technology (NIST).

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Journal Reference:

1. Constantine Y Khripin, Jeffrey A. Fagan, Ming Zheng. Spontaneous Partition of Carbon Nanotubes in Polymer-Modified Aqueous Phases. Journal of the American Chemical Society, 2013; : 130423102819007 DOI: 10.1021/ja402762e

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

Source: http://feeds.sciencedaily.com/~r/sciencedaily/~3/Wv5zT60mZqw/130501145146.htm

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Comcast gains 583,000 new subscribers, while revenues reach $15.3 billion for Q1 2013

Comcast had a dramatic Q4 last year when it announced the buyout of NBCUniversal for $16.7 billion along with the purchase of New York's iconic 30 Rockefeller Plaza. Still, it's the cable TV and internet business that pays the freight, and that side of the Comcast's operations didn't it let it down in Q1 2013 thanks to a 6.7 percent bump in revenue to $10.2 billion along with 583,000 new subscribers. Other operations didn't fare as well, as revenue for NBCUniversal dropped 2.4 percent to $5.3 billion, but the overall picture was still pretty sunny, as the communications giant saw an 11.2 percent increase in operating income over last year to $3.1 billion. If you want to see a breakdown by division, check the source for more.

Filed under: Home Entertainment, Internet, HD

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Source: Comcast

Source: http://www.engadget.com/2013/05/01/comcast-Q1-2013-earnings/?utm_medium=feed&utm_source=Feed_Classic&utm_campaign=Engadget

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Country superstar George Jones dead at 81

NASHVILLE, Tenn. (AP) ? When it comes to country music, George Jones was The Voice.

Other great singers have come and gone, but this fact remained inviolate until Jones passed away Friday at 81 in a Nashville hospital after a year of ill health.

"Today someone else has become the greatest living singer of traditional country music, but there will never be another George Jones," said Bobby Braddock, the Country Music Hall of Fame songwriter who provided Jones with 29 songs over the decades. "No one in country music has influenced so many other artists."

He did it with that voice. Rich and deep, strong enough to crack like a whip, but supple enough to bring tears. It was so powerful, it made Jones the first thoroughly modern country superstar, complete with the substance abuse problems and rich-and-famous celebrity lifestyle that included mansions, multiple divorces and ? to hear one fellow performer tell it ? fistfuls of cocaine.

He was a beloved and at times a notorious figure in Nashville and his problems were just as legendary as his songs. But when you dropped the needle on one of his records, all that stuff went away. And you were left with The Voice.

"He just knows how to pull every drop of emotion out of it of the songs if it's an emotional song or if it's a fun song he knows how to make that work," Alan Jackson said in a 2011 interview. "It's rare. He was a big fan of Hank Williams Sr. like me. He tried to sing like Hank in the early days. I've heard early cuts. And the difference is Hank was a singer and he was a great writer, but he didn't have that natural voice like George. Not many people do. That just sets him apart from everybody."

That voice helped Jones achieve No. 1 songs in four separate decades, 1950s to 1980s. And its qualities were admired by more than just his fellow country artists but by Frank Sinatra, Pete Townshend, Elvis Costello, James Taylor and countless others. "If we all could sound like we wanted to, we'd all sound like George Jones," Waylon Jennings once sang.

Word of his death spread Friday morning as his peers paid tribute.

Merle Haggard put it best, perhaps: "The world has lost the greatest country singer of all time. Amen."

"The greatest voice to ever grace country music will never die," Garth Brooks said. "Jones has a place in every heart that ever loved any kind of music."

And Dolly Parton added, "My heart is absolutely broken. George Jones was my all time favorite singer and one of my favorite people in the world."

In Jones' case, that's not hyperbole. In a career that lasted more than 50 years, "Possum" evolved from young honky-tonker to elder statesman as he recorded more than 150 albums and became the champion and symbol of traditional country music, a well-lined link to his hero, Williams.

Jones survived long battles with alcoholism and drug addiction, brawls, accidents and close encounters with death, including bypass surgery and a tour bus crash that he only avoided by deciding at the last moment to take a plane.

His failure to appear for concerts left him with the nickname "No Show Jones," and he later recorded a song by that name and often opened his shows by singing it. His wild life was revealed in song and in his handsome, troubled face, with its dark, deep-set eyes and dimpled chin.

In song, like life, he was rowdy and regretful, tender and tragic. His hits included the sentimental "Who's Gonna Fill Their Shoes," the foot-tapping "The Race is On," the foot-stomping "I Don't Need Your Rockin' Chair," the melancholy "She Thinks I Still Care," the rockin' "White Lightning," and the barfly lament "Still Doing Time." Jones also recorded several duets with Tammy Wynette, his wife for six years, including "Golden Ring," ''Near You," ''Southern California" and "We're Gonna Hold On." He also sang with such peers as Willie Nelson and Merle Haggard and with Costello and other rock performers.

But his signature song was "He Stopped Loving Her Today," a weeper among weepers about a man who carries his love for a woman to his grave. The 1980 ballad, which Jones was sure would never be a hit, often appears on surveys as the most popular country song of all time and won the Country Music Association's song of the year award an unprecedented two years in a row.

Jones won Grammy awards in 1981 for "He Stopped Loving Her Today" and in 1999 for "Choices." He was elected to the Country Music Hall of Fame in 1992 and in 2008 was among the artists honored in Washington at the Kennedy Center.

He was in the midst of a yearlong farewell tour when he passed away. He was scheduled to complete the tour in November with an all-star packed tribute in Nashville. Stars lined up to sign on to the show, many remembering kindnesses over the years. Kenny Chesney thinks Jones may have one of the greatest voices in not just country history, but music history. But he remembers Jones for more than the voice. He was picked for a tour with Jones and Wynette early in his career and cherishes the memory of being invited to fly home on Jones' private jet after one of the concerts.

"I remember sitting there on that jet, thinking, 'This can't be happening,' because he was George Jones, and I was some kid from nowhere," Chesney said in an email. "I'm sure he knew, but he was generous to kids chasing the dream, and I never forgot it."

Jones was born Sept. 12, 1931, in a log house near the east Texas town of Saratoga, the youngest of eight children. He sang in church and at age 11 began performing for tips on the streets of Beaumont, Texas. His first outing was such a success that listeners tossed him coins, placed a cup by his side and filled it with money. Jones estimated he made more than $24 for his two-hour performance, enough to feed his family for a week, but he used up the cash at a local arcade.

"That was my first time to earn money for singing and my first time to blow it afterward," he recalled in "I Lived to Tell it All," a painfully self-critical memoir published in 1996. "It started what almost became a lifetime trend."

The family lived in a government-subsidized housing project, and his father, a laborer, was an alcoholic who would rouse the children from bed in the middle of the night to sing for him. His father also noted that young George liked music and bought him a Gene Autry guitar, with a horse and lariat on the front that Jones practiced on obsessively.

He got his start on radio with husband and wife team Eddie & Pearl in the late 1940s. Hank Williams once dropped by the studio to promote a new record, and Jones was invited to back him on guitar. When it came time to play, he froze.

"Hank had 'Wedding Bells' out at the time," Jones recalled in a 2003 Associated Press interview. "He started singing it, and I never hit the first note the whole song. I just stared."

After the first of his four marriages failed, he enlisted in the Marine Corps in 1951 and served three years. He cut his first record when he got out, an original fittingly called "No Money in This Deal."

He had his first hit with "Why Baby Why" in 1955, and by the early '60s Jones was one of country music's top stars.

"I sing top songs that fit the hardworking, everyday loving person. That's what country music is about," Jones said in a 1991 AP interview. "My fans and real true country music fans know I'm not a phony. I just sing it the way it is and put feeling in it if I can and try to live the song."

Jones was married to Wynette, his third wife, from 1969 to 1975. (Wynette died in 1998.) Their relationship played out in Nashville like a country song, with hard drinking, fights and reconciliations. Jones' weary knowledge of domestic warfare was immortalized in such classics as "The Battle," set to the martial beat of "The Battle Hymn of the Republic."

After one argument, Jones drove off on a riding mower in search of a drink because Wynette had taken his car keys to keep him from carousing. Years earlier, married to his second wife, he had also sped off on a mower in search of a drink. Jones referred to his mowing days in the 1996 release, "Honky Tonk Song," and poked fun at himself in four music videos that featured him aboard a mower.

His drug and alcohol abuse grew worse in the late '70s, and Jones had to file for bankruptcy in 1978. A manager had started him on cocaine, hoping to counteract his boozy, lethargic performances, and Jones was eventually arrested in Jackson, Miss., in 1983 on cocaine possession charges. He agreed to perform a benefit concert and was sentenced to six months probation. In his memoir, "Satan is Real," Charlie Louvin recounts being offered a fistful of cocaine by Jones backstage at a concert.

"In the 1970s, I was drunk the majority of the time," Jones wrote in his memoir. "If you saw me sober, chances are you saw me asleep."

In 1980, a 3-minute song changed his life. His longtime producer, Billy Sherrill, recommended he record "He Stopped Loving Her Today," a ballad by Braddock and Curly Putnam. The song took more than a year to record, partly because Jones couldn't master the melody, which he confused with Kris Kristofferson's "Help Me Make it Through the Night," and partly because he was too drunk to recite a brief, spoken interlude ("She came to see him one last time/And we all wondered if she would/And it kept running through my mind/This time he's over her for good.")

"Pretty simple, eh?" Jones wrote in his memoir. "I couldn't get it. I had been able to sing while drunk all of my life. I'd fooled millions of people. But I could never speak without slurring when drunk. What we needed to complete that song was the narration, but Billy could never catch me sober enough to record four simple spoken lines."

Jones was convinced the song was too "morbid" to catch on. But "He Stopped Loving Her Today," featuring a string section that hummed, then soared, became an instant standard and virtually canonized him. His concert fee jumped from $2,500 a show to $25,000.

"There is a God," he recalled.

___

Italie contributed from New York.

Source: http://news.yahoo.com/country-superstar-george-jones-dead-81-164554929.html

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Earth's Core Far Hotter Than Thought

Semantics, yes, but you can't grade "hotness" on either the Fahrenheit or Celsius scales by a percentage; otherwise 1 degree is infinitely "hotter" than 0 degrees!

To be fair, in Kelvin this is a 19% increase, so the semantic difference seems irrelevant. To put it in perspective, though, a 20% increase from room temperature (25 C or 298 K) would be 85 C (358 K); I'm pretty sure you'd agree that's "far" hotter!

Source: http://rss.slashdot.org/~r/Slashdot/slashdotScience/~3/WstB3EEEjKg/story01.htm

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NATO: 4 service members killed in plane crash

KABUL, Afghanistan (AP) ? A plane crashed in southern Afghanistan on Saturday, killing four international service members, NATO said.

Initial reporting indicated there was no enemy activity in the area at the time, but coalition personnel secured the site and the cause of the crash was being investigated, NATO said.

The brief statement did not identify the nationalities of the victims, or say where the plane went down.

However, Mohammad Jan Rasoulyar, deputy governor of the southern province of Zabul, said an aircraft belonging to foreign forces crashed Saturday afternoon in Shah Joy district. He said the site had been surrounded by international forces.

Source: http://news.yahoo.com/nato-4-members-killed-plane-crash-170208072.html

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Bird navigation: Great balls of iron

Apr. 25, 2013 ? Every year millions of birds make heroic journeys guided by Earth's magnetic field. How they detect magnetic fields has puzzled scientists for decades. Today, the Keays lab at the Research Institute of Molecular Pathology in Vienna has added some important pieces to this puzzle.

Their work, published in Current Biology, reports the discovery of iron balls in sensory neurons. These cells, called hair cells, are found in the ear and are responsible for detecting sound and gravity. Remarkably, each cell has just one iron ball, and it is in the same place in every cell. "It's very exciting. We find these iron balls in every bird, whether it's a pigeon or an ostrich" adds Mattias Lauwers who discovered them "but not in humans." It is an astonishing finding, despite decades of research these conspicuous balls of iron had not been discovered.

This finding builds on previous work by the lab of David Keays who last year showed that iron-rich cells in the beak of pigeons that were believed to be the magnetic sensors, were really just blood cells. "These cells are much better candidates, because they're definitely neurons. But we're a long way off to understanding how magnetic sensing works -- we still don't know what these mysterious iron balls are doing." said Dr Keays. "Who knows, perhaps they are the elusive magnetoreceptors" muses Dr Keays "only time will tell."

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The above story is reprinted from materials provided by Research Institute of Molecular Pathology.

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Journal Reference:

1. Mattias Lauwers, Paul Pichler, Nathaniel?Bernard Edelman, Guenter?Paul Resch, Lyubov Ushakova, Marion?Claudia Salzer, Dominik Heyers, Martin Saunders, Jeremy Shaw, David?Anthony Keays. An Iron-Rich Organelle in the Cuticular Plate of Avian Hair Cells. Current Biology, 2013; DOI: 10.1016/j.cub.2013.04.025

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

Source: http://feeds.sciencedaily.com/~r/sciencedaily/strange_science/~3/IUgVDYZL2Mo/130426073811.htm

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