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Creating electricity with caged atoms

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Clathrates are crystals consisting of tiny cages in which single atoms can be enclosed. These atoms significantly alter the material properties of the crystal. By trapping cerium atoms in a clathrate, scientists at the Vienna University of Technology have created a material which has extremely strong thermoelectric properties. It can be used to turn waste heat into electricity. (from phys.org)

A lot of energy is wasted when machines turn hot, unnecessarily heating up their environment. Some of this thermal energy could be harvested using thermoelectric materials; they create electric current when they are used to bridge hot and cold objects. At the Vienna University of Technology (TU Vienna), a new and considerably more efficient class of thermoelectric materials can now be produced. It is the material’s very special crystal structure that does the trick, in connection with an astonishing new physical effect; in countless tiny cages within the crystal, cerium atoms are enclosed. These trapped magnetic atoms are constantly rattling the bars of their cage, and this rattling seems to be responsible for the material’s exceptionally favourable properties.

“Clathrates” is the technical term for crystals, in which host atoms are enclosed in cage-like spaces. “These clathrates show remarkable thermal properties”, says Professor Silke Bühler-Paschen (TU Vienna). The exact behaviour of the material depends on the interaction between the trapped atoms and the cage surrounding them. “We came up with the idea to trap cerium atoms, because their magnetic properties promised particularly interesting kinds of interaction”, explains Bühler-Paschen.
For a long time, this task seemed impossible. All earlier attempts to incorporate magnetic atoms such as the rare-earth metal cerium into the clathrate structures failed. With the help of a sophisticated crystal growth technique in a mirror oven, Professor Andrey Prokofiev (TU Vienna) has now succeeded in creating clathrates made of barium, silicon and gold, encapsulating single cerium atoms.

The thermoelectric properties of the novel material have been tested. Thermoelectrics work when they connect something hot with something cold: “The thermal motion of the electrons in the material depends on the temperature”, explains Bühler-Paschen. “On the hot side, there is more thermal motion than on the cold side, so the electrons diffuse towards the colder region. Therefore, a voltage is created between the two sides of the thermoelectric material.”

Experiments show that the cerium atoms increase the material’s thermopower by 50%, so a much higher voltage can be obtained. Furthermore, the thermal conductivity of clathrates is very low. This is also important, because otherwise the temperatures on either side would equilibrate, and no voltage would remain.

“The reason for these remarkably good material properties seem to lie in a special kind of electron-electron correlation – the so-called Kondo effect”, Silke Bühler-Paschen believes. The electrons of the cerium atom are quantum mechanically linked to the atoms of the crystal. Actually, the Kondo effect is known from low temperature physics, close to absolute zero temperature. But surprisingly, these quantum mechanical correlations also play an important role in the novel clathrate materials, even at a temperature of hundreds of degrees Celcius.

“The rattling of the trapped cerium atoms becomes stronger as the temperature increases”, says Bühler-Paschen. “This rattling stabilizes the Kondo effect at high temperatures. We are observing the world’s hottest Kondo effect.”

The research team at TU Vienna will now try to achieve this effect also with different kinds of clathrates. In order to make the material commercially more attractive, the expensive gold could possibly be substituted by other metals, such as copper. Instead of cerium, a cheaper mixture of several rare-earth elements could be used. There are high hopes that such designer clathrates can be technologically applied in the future, to turn industrial waste heat into valuable electrical energy.

First Flight of Japanese ‘Artificial Intelligence’ Rocket

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More than five decades of rocketry from Japan’s Kagoshima Prefecture will continue with the maiden voyage of the new Epsilon vehicle to insert an ultraviolet observatory into low-Earth orbit to observe Venus, Mars, and Jupiter. The 700-pound Spectroscopic Planet Observatory for Recognition of Interaction of Atmosphere (SPRINT-A) will utilize an extreme ultraviolet spectrometer and guiding camera and will spend about a year in orbit. Yet as exciting as this scientific payload may be, the Epsilon itself carries much promise for the Japan Aerospace Exploration Agency (JAXA). The rocket’s project manager has described it as a vehicle which will literally “open up the future.” (from americaspace.com)

The 78-foot-tall Epsilon vehicle marries one Solid Rocket Booster (SRB) from the H-IIA rocket as its first stage with upper-stage hardware from the 2006-retired M-V rocket. As a launcher, it is reportedly capable of transporting up to 2,600 pounds of payload into low-Earth orbit. Originally scheduled to fly on 22 August from the Uchinoura Space Center in Kagoshima, its launch date was postponed as JAXA required additional time to resolve a problem surrounding an incorrect line routing in the signal relay equipment used to check Epsilon’s critical functions.

Yet it is the cost savings—estimated to be about 30 percent better than the M-V—which JAXA is particularly keen to stress. The launch is estimated to cost in the range of 5.3 billion yen ($53 million), significantly lower than the 7 billion yen ($70 million) fee for an M-V, and such savings have been made partially through the streamlining of launch procedures. It is anticipated that subsequent Epsilon launches may bring costs still lower, into the 3.0-3.8 billion yen ($30-38 million) bracket.

Japan has been flying solid-fueled “pencil” rockets since the mid-1950s, and Epsilon stands firmly upon the shoulders of previous titans and utilizes new, cutting-edge technology. “We aim to greatly simplify the launch system by using artificial intelligence,” said Project Manager Yasuhiro Morita, quoted in a JAXA interview. Morita is a professor in the Department of Space Systems and Astronautics with the Institute of Space and Astronautical Science (ISAS), a subdivision of JAXA. “Today, a typical scenario is hundreds of people assembling at the launch center and working for several months in preparation for a launch. On the day of the launch, dozens of people are in the control room, monitoring every aspect. The Epsilon launch vehicle will drastically change this picture.” By running autonomous health and other checks, supported by artificial intelligence, it is hoped that control personnel with ultimately be able to run the whole show from a pair of laptop computers.

“Rockets use technology from many generations ago,” explained Morita, “so they are like a showcase of deficiencies. There has long been a notion that new technology should be tested over an extended period of time before being used in actual launch vehicles. Consequently, the latest artificial intelligence applications have not yet been employed in rockets. The Epsilon launch vehicle will be the first rocket with artificial intelligence that will perform checks and monitor its own operation autonomously.”

Moving forward from desktop and laptop computers, it is Morita’s hope that by 2017 the Epsilon will be in a position to “monitor and judge its own flight safety autonomously, so that we can remove the radar and antenna used to track and send commands to the rocket.” By assigning further artificial intelligence assets to the vehicle—including the capability to act as its own Range Safety Officer and destroy itself in the event of off-nominal events—the Epsilon will eliminate the need for expensive, ground-based hardware and further simplify launch and tracking facilities.

As the maiden flight of the Epsilon, the mission has attracted a great deal of publicity, both in Japan and around the world. In April-May 2013, it was the subject of a New Launch Vehicle Message Posting Campaign. Some 5,812 messages—the vast majority in Japanese and a few hundred in other languages—were received as part of an effort to share individuals’ “expectations, hopes, dreams, or feelings toward our new launch vehicle.” JAXA then processed these messages into strings of small letters on the Epsilon itself, in order to “make people feel more familiar with space, gaining more understanding of and support for space programs.” According to JAXA, this was a key goal of the Epsilon project.

Testing and processing of the new rocket has gone relatively smoothly, with its upper stage motor static-fired in September 2011 to evaluate the performance of insulation material, followed by last October’s extension test of the second stage motor nozzle. More recently, in April 2013, it was reported that a full-scale model of Epsilon had been transferred from the maintenance tower to the launch pad to demonstrate rollout and other pre-launch protocols.

Liftoff will begin with the ignition of the first-stage’s Nissan-built solid motor, producing an estimated 505,000 pounds of thrust. This will burn for about two minutes, after which the second stage—a modified version of the M-V’s M-34 upper stage, also solid-fueled, with an extendible nozzle—will pick up the thrust for 104 seconds to execute the next stage of the rocket’s climb to orbit. The third stage, based upon the KM-V2b upper stage from the M-V, will then fire for approximately 91 seconds, after which a hydrazine-fed small liquid propulsion system will provide the final boost. According to JAXA’s Epsilon press kit, this final stage will perform two burns and SPRINT-A will be separated from the vehicle about 61 minutes after launch.

The satellite is expected to operate for about a year in an orbit of 590-715 miles, inclined 31 degrees to the equator, from which it will observe the magnetospheric environments of Venus, Mars, and Jupiter. “Capturing the extreme ultraviolet rays emitted from a planet and its periphery, which cannot be observed from the ground, allows us to collect information on the atmosphere that flows into space and the magnetosphere covering the planet,” noted JAXA in its SPRINT-A mission brochure. “This enables us to analyze the composition of the atmosphere and the behavior of the magnetosphere. Our primary theme is each planet’s magnetosphere, the region where the magnetic field of a planet has influence.” Jupiter’s magnetic field is 10,000 times stronger than that of Earth and rotates on its axis at a high rate of around 10 hours per cycle, whereas those of Venus and Mars are far weaker. SPRINT-A will focus on the interactions between planetary magnetospheres and the solar wind.

Guardian says Britain forced it to destroy Snowden material

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The editor of The Guardian Rusbridger leaves Downing Street in London

WASHINGTON/RIO DE JANEIRO (Reuters) – The Guardian, a major outlet for revelations based on leaks from former U.S. intelligence contractor Edward Snowden, says the British government threatened legal action against the newspaper unless it either destroyed the classified documents or handed them back to British authorities.(from news.yahoo.com)

In an article posted on the British newspaper’s website on Monday, Guardian editor Alan Rusbridger said that a month ago, after the newspaper had published several stories based on Snowden’s material, a British official advised him: “You’ve had your fun. Now we want the stuff back.”

Rusbridger’s disclosure follows Sunday’s detainment at London’s Heathrow Airport under British anti-terrorism laws of David Miranda, domestic partner of U.S. journalist and Guardian writer Glenn Greenwald.

Miranda, a Brazilian citizen in transit from Berlin to Brazil, said he was released without charge after nine hours of questioning but minus his laptop, cellphone and memory sticks.

Greenwald, who met face to face in Hong Kong with Snowden and has written or co-authored many of the newspaper’s stories about U.S. surveillance of global communications, vowed on Monday to publish more documents and said Britain will “regret” detaining his partner.

Rusbridger said that after further talks with the British government, two “security experts” from Government Communications Headquarters, the British equivalent of the ultra-secretive U.S. National Security Agency, visited the Guardian’s London offices.

In the building’s basement, Rusbridger wrote, government officials watched as computers which contained material provided by Snowden were physically pulverized. “We can call off the black helicopters,” Rusbridger says one of the officials joked.

A source familiar with the event said Guardian employees destroyed the computers as government security experts looked on.

Rusbridger, in his article, said he told British officials that due to the nature of “international collaborations” among journalists, it would remain possible for media organizations to “take advantage of the most permissive legal environments.” Henceforth, he said, the Guardian “did not have to do our reporting from London.”

A source familiar with the matter said that this meant British authorities were on notice that the Guardian was likely to continue to report on the Snowden revelations from outside British government jurisdiction.

‘HAD YOUR DEBATE’

Rusbridger said that in meetings with British officials, before the computers were destroyed, he told them the Guardian could not do its journalistic duty if it gave in to the government’s requests.

In response, he wrote, a government official told him that the newspaper had already achieved the aim of sparking a debate on government surveillance. “You’ve had your debate. There’s no need to write any more,” the unnamed official was quoted as saying.

The Guardian’s decision to publicize the government threat – and the newspaper’s assertion that it can continue reporting on the Snowden revelations from outside of Britain – appears to be the latest step in an escalating battle between the news media and governments over reporting of secret surveillance programs.

One U.S. security official told Reuters that one of the main purposes of the British government’s detention and questioning of Miranda was to send a message to recipients of Snowden’s materials, including the Guardian, that the British government was serious about trying to shut down the leaks.

White House spokesman Josh Earnest told reporters on Monday that while the United States did not ask British authorities to detain Miranda, British officials had given the United States a “heads up” about the British government’s plan to question him.

Greenwald, asked by a reporter if the detention of his partner would deter him from future reporting, said the opposite would happen.

“I will be far more aggressive in my reporting from now. I am going to publish many more documents. I am going to publish things on England, too. I have many documents on England’s spy system,” Greenwald, speaking in Portuguese, told reporters at Rio de Janeiro’s airport where he met Miranda upon his return to Brazil.

During Miranda’s trip to Berlin, which the Guardian said it had paid for, he visited with Laura Poitras, an independent film-maker who was the first journalist to interact with Snowden. Poitras co-authored stories based on Snowden’s material for the Washington Post and the German magazine Der Spiegel.

Greenwald told the New York Times that Miranda went to Berlin to deliver materials downloaded by Snowden to Poitras and to acquire from Poitras a different set of materials for delivery to Greenwald, who lives with Miranda near Rio de Janeiro.

Greenwald told the Forbes website that “everything” Miranda had “was heavily encrypted.” Greenwald did not immediately respond to an email from Reuters requesting comment.

While British authorities confirmed that Miranda had been detained under an anti-terrorism law, they did not further explain their actions. Brazil’s government complained about Miranda’s detention in a statement on Sunday that said the use of the British anti-terrorism law was unjustified.

George Duke Dead: Legendary Musician Dies At 67

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George Duke, legendary jazz, R&B, funk musician has died at age 67.
(from huffingtonpost.com)

According to New York Daily News, Duke passed away on Monday, August 5, in Los Angeles. His cause of death has not yet been determined.

Throughout his career, which spanned over 40 years, the eclectic musician crafted a string of hits including the timeless classic “No Rhyme No Reason,” and worked alongside music legends including Smokey Robinson, Gladys Knight, Anita Baker, Miles Davis, Michael Jackson and Barry Manilow, to name a few.

Former Supremes member, Sherrie Payne, who was a close family friend, released a statement on the news of Duke’s passing;

I just received the devastating and sad news that the great musician, George Duke, passed away this evening at St. John’s hospital in L.A. It was just one year earlier, July 18th, that his beloved wife and my friend, Corine, went to be with the Lord. Please keep his sons, Rasheed and John, in your prayers.

Duke released his latest opus, “DreamWeaver,” which was dedicated to his late wife, Corine, who died a year ago from cancer.

Duke’s music will continue to live on through a new generation of listeners and has been sampled by many artists including Kanye West, Daft Punk, and A Tribe Called Quest among many others.

Hot-Fire Tests Show 3-D Printed Rocket Parts Rival Traditionally Manufactured Parts

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Propulsion engineer Sandra Greene, left, and test engineer Cynthia Sprader recently completed a series of test firings at NASA’s Marshall Space Flight Center in Huntsville, Alabama.(from www.nasa.gov)

What can survive blazing temperatures of almost 6,000 degrees Fahrenheit without melting? What did not break apart at extreme pressures? What is made by a new process that forms a complex part in just one piece? What takes less than three weeks to go from manufacturing to testing? What can reduce the costs of expensive rocket parts by 60 percent or more?

Answer: 3-D printed parts

Engineers know that 3-D printed rocket parts have the potential to save NASA and industry money and to open up new affordable design possibilities for rockets and spacecraft. But until recently, no one had tested rocket parts critical to engine combustion in a hot-fire environment.

NASA engineers at the Marshall Space Flight Center in Huntsville, Ala., not only put rocket engine parts to the test but also were able to compare their performance to parts made the old-fashioned way with welds and multiple parts during planned subscale acoustic tests for the Space Launch System (SLS) heavy-lift rocket. In little more than a month, Marshall engineers built two subscale injectors with a specialized 3-D printing machine and completed 11 mainstage hot-fire tests, accumulating 46 seconds of total firing time at temperatures nearing 6,000 degrees Fahrenheit while burning liquid oxygen and gaseous hydrogen.

“We saw no difference in performance of the 3-D printed injectors compared to the traditionally manufactured injectors,” said Sandra Elam Greene, the propulsion engineer who oversaw the tests and inspected the components afterward. “Two separate 3-D printed injectors operated beautifully during all hot-fire tests.”

Post-test inspections showed the injectors remained in such excellent condition and performed so well the team will continue to put them directly in the line of fire. In addition to the SLS acoustic tests, Greene and her team tested a more complex assembly of a 3-D printed injector and thrust chamber liner made by Directed Manufacturing, Inc., of Austin, Texas. Marshall engineers transferred a second 3-D printed injector to NASA’s Stennis Space Center in Mississippi, where it will continue to accumulate hot-fire time to test its durability.

“Rocket engines are complex, with hundreds of individual components that many suppliers typically build and assemble, so testing an engine component built with a new process helps verify that it might be an affordable way to make future rockets,” said Chris Singer, director of the Marshall Center’s Engineering Directorate. “The additive manufacturing process has the potential to reduce the time and cost associated with making complex parts by an order of magnitude.”

Traditional subscale rocket injectors for early SLS acoustic tests took six months to fabricate, had four parts, five welds and detailed machining and cost more than $10,000 each. Marshall materials engineers built the same injector in one piece by sintering Inconel steel powder with a state-of-the-art 3-D printer. After minimal machining and inspection with computer scanning, it took just three weeks for the part to reach the test stand and cost less than $5,000 to manufacture.

“It took about 40 hours from start to finish to make each injector using a 3-D printing process called selective laser melting, and another couple of weeks to polish and inspect the parts,” explained Ken Cooper, a Marshall materials engineer whose team made the part. “This allowed the propulsion engineers to take advantage of an existing SLS test series to examine how 3-D printed parts performed compared to traditional parts with a similar design.”

Since additive manufacturing machines have has become more affordable, varied, and sophisticated, this materials process now offers many possibilities for making every phase of NASA missions more affordable. The SLS injector tests are just one example of NASA’s efforts to fabricate and test 3-D printed parts in relevant environments similar to those experienced during NASA missions. The SLS injector test series complements a series of liquid oxygen and gaseous hydrogen rocket assembly firings at NASA’s Glenn Research Center in Cleveland, which hot-fire tested an additively manufactured, select laser melted injector developed through collaboration of industry and government agencies. A J-2X engine exhaust port cover made at the Marshall Center became the first 3-D printed part tested during a full-scale engine hot-fire test at NASA’s Stennis Center. Marshall materials engineers are currently making a baffle critical for pogo vibration mitigation; it will be tested at Marshall and Stennis and is a potential candidate for the first SLS mission in 2017. Marshall engineers are finishing up ground tests with Made in Space, a Moffett Field, California company working with NASA to develop and test a 3-D printer that will build tools on the International Space Station next year. NASA’s Johnson Space Center in Houston is even exploring printing food in space.

“At NASA, we recognize ground-based and in-space additive manufacturing offer the potential for new mission opportunities, whether printing rocket parts, tools or entire spacecraft,” Singer said. “Additive manufacturing will improve affordability from design and development to flight and operations, enabling every aspect of sustainable long-term human space exploration.”

NASA is a leading partner in the National Network for Manufacturing Innovation and the Advanced Manufacturing Initiative, which explores using additive manufacturing and other advanced materials processes to reduce the cost of spaceflight. For more information about the National Network for Manufacturing Innovation, visit: http://manufacturing.gov/nnmi.html

78,000 sign up for one-way mission to Mars

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Amersfoort, 7th May 2013 – Just two weeks into the nineteen week application period, more than seventy-eight thousand people have applied to the Mars One astronaut selection program in the hope of becoming a Mars settler in 2023.

Mars One has received applications from over 120 countries. Most applications come from USA (17324), followed by China (10241), United Kingdom (3581), Russia, Mexico, Brazil, Canada, Colombia, Argentina and India.Bas Lansdorp, Mars One Co-Founder and CEO said: “With seventy-eight thousand applications in two weeks, this is turning out to be the most desired job in history. These numbers put us right on track for our goal of half a million applicants.”

“Mars One is a mission representing all humanity and its true spirit will be justified only if people from the entire world are represented. I’m proud that this is exactly what we see happening,” he said.

As part of the application every applicant is required to explain his/her motivation behind their decision go to Mars in an one minute video. Many applicants are choosing to publish this video on the Mars One website. These are openly accessible on applicants.mars-one.com.

“Applicants we have received come from a very wide range of personalities, professions and ages. This is significant because what we are looking for is not restricted to a particular background. From Round 1 we will take forward the most committed, creative, resilient and motivated applicants,” said Dr. Norbert Kraft, Mars One Chief Medical Officer.

Mars One will continue to receive online applications until August 31st 2013. From all the applicants in Round 1, regional reviewers will select around 50-100 candidates for Round 2 in each of the 300 geographic regions in the world that Mars One has identified.

Four rounds make the selection process, which will come to an end in 2015; Mars One will then employ 28-40 candidates, who will train for around 7 years. Finally an audience vote will elect one of groups in training to be the envoys of humanity to Mars.