Wednesday, September 16, 2009

IMPROVED SEISMOLOGY TOOLS CAN DETECT AND LOCATE LOW-YIELD NUCLEAR EXPLOSIONS

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Lawrence Livermore National Laboratory is leading a joint project with Los Alamos and Sandia national laboratories, as well as the Air Force Technical Applications Center (AFTAC) and Quantum Technology Sciences, Inc., to improve the accuracy of regional seismic travel time (RSTT) predictions to detect and locate low-yield nuclear explosions.

While seismic research is most often associated with earthquakes, seismic technology is also the primary means to detect, locate and identify underground nuclear explosions.

Underground nuclear testing plays a pivotal role in the persistent and well-documented efforts by states to develop and improve explosive nuclear devices.

Nuclear tests are no longer frequent. However, there are 30- 40 earthquakes of magnitude 4 and greater every day — about 10,000 per year. A magnitude 4 earthquake releases energy on the order of a one-kiloton nuclear explosion. Identification and location of the rare, and possibly covert nuclear test, within the cacophony of natural and man-made background seismic activity, is a major national security scientific challenge that NNSA and its labs are in a unique position to meet.

Scientists study the seismic traces (waveform records of the surface ground motion as a function of time, acquired by digital equipment) from networks of seismometers all over the world.

The long-term effort to improve seismic event location accuracy significantly increases the accuracy of RSTT predictions. The newly developed RSTT model embodies three-dimensional variations in seismic wave speed in the earth's crust as well as lateral variability in seismic-wave speed in the earth's upper mantle.

The RSTT model increases the location accuracy of small events, previously undetectable at great distance. Tests across Eurasia show that the RSTT model improves median location accuracy by 46 percent (from 17.3 km using a standard one-dimensional model to 9.3 km using the RSTT model).

NNSA efforts have reduced regional location error for small yield events to a level that, until recently, was only achieved for large, globally recorded events.

This NNSA-funded effort has resulted in a significant improvement in regional seismic event location accuracy and further improvement can be expected as complementary research projects mature, thus improving our ability to detect lower yield events.

(Photo: John Dubinski and Larry Widrow)

Lawrence Livermore National Laboratory

WHAT'S SMELLY BUT CAN FUEL A CAR?

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Driving home from a seminar on fuel cell technology, Gerardine Botte was struck with a notion. Her idea was based on water electrolysis, a process used to produce hydrogen energy from water. Botte, an associate professor of chemical and biomolecular engineering in the Russ College of Engineering and Technology, took the concept to the next level: Instead of clean water, what if it were possible to use wastewater?

“You could remove the ammonia from wastewater, convert it to hydrogen energy, and it would be better, because you’d be remediating and producing clean energy,” says Botte.

What resulted was a first-of-its-kind fuel cell technology, known as the “ammonia electrolytic cell,” that allows hydrogen to be produced on demand. It’s an efficient and environmentally sound process; compared to water electrolysis, ammonia electrolysis consumes 95 percent less energy and produces more hydrogen.

The ammonia itself comes from a renewable supply. Botte estimates more than 5 million tons of ammonia enter the waste stream as human and animal urine each year in the United States.

If it seems like an unlikely fuel source, Botte will do her best to convince you otherwise. “I think ammonia is our future fuel,” she says. “It’s green, renewable, and we know how to transport it and work with it.”

Since its inception, Botte’s idea of ammonia electrolysis has blossomed into several projects. At Ohio University, she enlists the help of five graduate students who each cover specific branches of ammonia electrolysis research, including potential automobile and residential applications.

In November, Botte’s Electrochemical Engineering Research Laboratory received a $2.23 million federal grant to adapt the concept for military use. Under the “Silent Camp Initiative,” she’ll work with the U.S. Army Engineer Research and Development Center’s Construction, Engineering Research Laboratory to provide backup power for training facilities and soldier camps at night.

The system could cut long-term costs for fuel and decrease susceptibility to attacks against fuel supply lines.

If successful, there could be promising potential for the commercialization of the ammonia electrolytic cell.

Botte takes pride in the fact that the cell had its beginnings at Ohio University. “It was born here and is unique to this university,” she says.

(Photo: Ohio University)

Ohio University

GIANT GALAXY HOSTS THE MOST DISTANT SUPERMASSIVE BLACK HOLE

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University of Hawaii (UH) astronomer Dr. Tomotsugu Goto and colleagues have discovered a giant galaxy surrounding the most distant supermassive black hole ever found. The galaxy, so distant that it is seen as it was 12.8 billion years ago, is as large as the Milky Way galaxy and harbours a supermassive black hole that contains at least a billion times as much matter as our Sun. The scientists set out their results in a paper in the journal Monthly Notices of the Royal Astronomical Society later this month.

Dr. Goto stated, "It is surprising that such a giant galaxy existed when the Universe was only one-sixteenth of its present age, and that it hosted a black hole one billion times more massive than the Sun. The galaxy and black hole must have formed very rapidly in the early Universe."

Knowledge of the host galaxies of supermassive black holes is important in order to understand the long-standing mystery of how galaxies and black holes have evolved together. Until now, studying host galaxies in the distant Universe has been extremely difficult because the blinding bright light from the vicinity of the black hole makes it more difficult to see the already faint light from the host galaxy.

Unlike smaller black holes, which form when a large star dies, the origin of the supermassive black holes remains an unsolved problem. A currently favoured model requires several intermediate black holes to merge. The host galaxy discovered in this work provides a reservoir of such intermediate black holes. After forming, supermassive black holes often continue to grow because their gravity draws in matter from surrounding objects. The energy released in this process accounts for the bright light emitted from the region around the black holes.

To see the supermassive black hole, the team of scientists used new red-sensitive Charge Coupled Devices (CCDs) installed in the Suprime-Cam camera on the Subaru telescope on Mauna Kea. Prof. Satoshi Miyazaki of the National Astronomical Observatory of Japan (NAOJ) is a lead investigator for the creation of the new CCDs and a collaborator on this project. He said, "The improved sensitivity of the new CCDs has brought an exciting discovery as its very first result."

A careful analysis of the data revealed that 40 percent of the near-infrared light observed (at the wavelength of 9100 Angstroms) is from the host galaxy itself and 60 percent is from the surrounding clouds of material (nebulae) illuminated by the black hole.

(Photo: Tomotsugu GOTO, University of Hawaii)

Royal Astronomical Society

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