Monthly Archives: August 2011

Drinking Water Regulation

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Are agencies assuring the safety of public drinking water? It has been said some fell down on the job both in establishing criteria for identifying contaminants of greatest public health concern, and in testing unregulated contaminants in ways that provide useful data for making regulatory decisions

Microstepping Madness

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A recent article describes a machine-tool manufacturer's use of step motors and microstepping drives in place of continuous motors, making note of how quietly the machines run. What's your experience with smooth-performing microstepping drives and step motors, and their ability to replace continuous

Driver Fatigue: an Alarming Situation

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Fatigue is a common cause of highway tractor trailer accidents. About one-quarter of commercial roadway accidents are due to drivers falling asleep at the wheel. That stark reality in mind, inventors in Denmark developed a dash-mounted alarm system that detects when a driver is about to fall asleep

Decision day for CST-100?s ride to orbit

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CST-100 illustration

Illustration of Boeing's proposed CST-100 commercial crew capsule.

Since unveiling its plans for developing a commercial crew spacecraft, Boeing has emphasized that its CST-100 spacecraft was launch vehicle agnostic: it could launch on an Atlas 5, Delta 4, or Falcon 9. And when ATK announced its plans in February for the Liberty launch vehicle, Boeing officials added it to the roster of vehicles compatible with the capsule. Now, however, the company plans to focus its attention on a single rocket.

At a media teleconference scheduled for noon Eastern time today, Boeing officials will announce the formal selection of the vehicle that will be used for the CST-100′s test flights in 2015 and operational missions to the ISS and other orbital destinations. This downselect is not surprising: at an April briefing, CST-100 program manager John Elbon said that they would select a specific vehicle to “really lay out the abort scenarios” and details associated with them.

The clear favorite in this vehicle competition is the Atlas 5. Two other Commercial Crew Development (CCDev) awardees, Blue Origin and Sierra Nevada, have already picked the Atlas 5 to launch their crewed spacecraft, and ULA has an unfunded CCDev agreement with NASA to continue work on human-rating that launcher. ULA also offers the Delta 4, which does have Boeing heritage, but does not appear to be the subject of active human-rating work. Falcon 9 would require Boeing to depend on a competitor, SpaceX, for its launcher, while ATK’s Liberty, unlike the other three, isn’t flying yet, raising the question of whether it would be ready by mid-decade or not.

NASA’s Chandra Observatory Images Gas Flowing Toward Black Hole

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The flow of hot gas toward a black hole has been clearly imaged for the first time in X-rays. The observations from NASA's Chandra X-ray Observatory will help tackle two of the most fundamental problems in modern astrophysics: understanding how black holes grow and how matter behaves in their intense gravity.
The black hole is at the center of a large galaxy known as NGC 3115, which is located about 32 million light years from Earth. A large amount of previous data has shown material falling toward and onto black holes, but none with this clear a signature of hot gas.
By imaging the hot gas at different distances from this supermassive black hole, astronomers have observed a critical threshold where the motion of gas first becomes dominated by the black hole's gravity and falls inward. This distance from the black hole is known as the "Bondi radius."
"It's exciting to find such clear evidence for gas in the grip of a massive black hole," said Ka-Wah Wong of the University of Alabama, who led the study that appears in the July 20th issue of The Astrophysical Journal Letters. "Chandra's resolving power provides a unique opportunity to understand more about how black holes capture material by studying this nearby object."
As gas flows toward a black hole, it becomes squeezed, making it hotter and brighter, a signature now confirmed by the X-ray observations. The researchers found the rise in gas temperature begins about 700 light years from the black hole, giving the location of the Bondi radius. This suggests the black hole in the center of NGC 3115 has a mass about two billion times that of the sun, making it the closest black hole of that size to Earth.
The Chandra data also show the gas close to the black hole in the center of the galaxy is denser than gas further out, as predicted. Using the observed properties of the gas and theoretical assumptions, the team then estimated that each year gas weighing about 2 percent the mass of the sun is being pulled across the Bondi radius toward the black hole.
Making certain assumptions about how much of the gas's energy changes into radiation, astronomers would expect to find a source that is more than a million times brighter in X-rays than what is seen in NGC 3115.
"A leading mystery in astrophysics is how the area around massive black holes can stay so dim, when there's so much fuel available to light up," said co-author Jimmy Irwin, also of the UA in Tuscaloosa. "This black hole is a poster child for this problem."
There are at least two possible explanations for this discrepancy. The first is that much less material actually falls onto the black hole than flows inside the Bondi radius. Another possibility is that the conversion of energy into radiation is much less efficient than is assumed.
Different models describing the flow of material onto the black hole make different predictions for how quickly the density of the gas is seen to rise as it approaches the black hole. A more precise determination of the rise in density from future observations should help astronomers rule out some of these models.

NASA’s WISE Mission Finds First Trojan Asteroid Sharing Earth’s Orbit

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Astronomers studying observations taken by NASA's Wide-field Infrared Survey Explorer (WISE) mission have discovered the first known "Trojan" asteroid orbiting the sun along with Earth.
Trojans are asteroids that share an orbit with a planet near stable points in front of or behind the planet. Because they constantly lead or follow in the same orbit as the planet, they never can collide with it. In our solar system, Trojans also share orbits with Neptune, Mars and Jupiter. Two of Saturn's moons share orbits with Trojans.
Scientists had predicted Earth should have Trojans, but they have been difficult to find because they are relatively small and appear near the sun from Earth's point of view.
"These asteroids dwell mostly in the daylight, making them very hard to see," said Martin Connors of Athabasca University in Canada, lead author of a new paper on the discovery in the July 28 issue of the journal Nature. "But we finally found one, because the object has an unusual orbit that takes it farther away from the sun than what is typical for Trojans. WISE was a game-changer, giving us a point of view difficult to have at Earth's surface."
The WISE telescope scanned the entire sky in infrared light from January 2010 to February 2011. Connors and his team began their search for an Earth Trojan using data from NEOWISE, an addition to the WISE mission that focused in part on near-Earth objects, or NEOs, such as asteroids and comets. NEOs are bodies that pass within 28 million miles (45 million kilometers) of Earth's path around the sun. The NEOWISE project observed more than 155,000 asteroids in the main belt between Mars and Jupiter, and more than 500 NEOs, discovering 132 that were previously unknown.
The team's hunt resulted in two Trojan candidates. One called 2010 TK7 was confirmed as an Earth Trojan after follow-up observations with the Canada-France-Hawaii Telescope on Mauna Kea in Hawaii.
The asteroid is roughly 1,000 feet (300 meters) in diameter. It has an unusual orbit that traces a complex motion near a stable point in the plane of Earth's orbit, although the asteroid also moves above and below the plane. The object is about 50 million miles (80 million kilometers) from Earth. The asteroid's orbit is well-defined and for at least the next 100 years, it will not come closer to Earth than 15 million miles (24 million kilometers). An animation showing the orbit is available at: http://www.nasa.gov/multimedia/videogallery/index.html?media_id=103550791 .
"It's as though Earth is playing follow the leader," said Amy Mainzer, the principal investigator of NEOWISE at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Earth always is chasing this asteroid around."
A handful of other asteroids also have orbits similar to Earth. Such objects could make excellent candidates for future robotic or human exploration. Asteroid 2010 TK7 is not a good target because it travels too far above and below the plane of Earth's orbit, which would require large amounts of fuel to reach it.
"This observation illustrates why NASA's NEO Observation program funded the mission enhancement to process data collected by WISE," said Lindley Johnson, NEOWISE program executive at NASA Headquarters in Washington. "We believed there was great potential to find objects in near-Earth space that had not been seen before."
NEOWISE data on orbits from the hundreds of thousands of asteroids and comets it observed are available through the NASA-funded International Astronomical Union's Minor Planet Center at the Smithsonian Astrophysical Observatory in Cambridge, Mass.
JPL manages and operates WISE for NASA's Science Mission Directorate in Washington. The principal investigator, Edward Wright, is a professor at the University of California, Los Angeles. The mission was selected under NASA's Explorers Program, which is managed by the agency's Goddard Space Flight Center in Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory in Logan, Utah.
The spacecraft was built by Ball Aerospace & Technologies Corp., Boulder, Colo. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.

For more information visit http://www.nasa.gov/mission_pages/WISE/news/wise20110727.html

3rd ‘Serrada Futurista’ in Folgaria

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Serrada Futurista

August 8 – 21, 2011
Serrada di Folgaria (TN)

Third installment of ‘Serrada Futurista’ – a celebration of Futurism in Folgaria.

Program

2nd installment (2010)

Una settimana di cultura, musica, teatro ed enogastronomia all’insegna del connubio tra movimento Futurista e lavorazione della pietra. E’ ‘Serrada Futurista’, alla terza edizione nell’omonima frazione di Folgaria, che riservera’ un’attenzione particolare al porfido. La manifestazione, nata in occasione del centenario della nascita del Futurismo, trova collocazione in uno dei luoghi che Fortunato Depero aveva eletto per le proprie vacanze e si terra’ dall’8 al 21 agosto.

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