Showing stories 76-97 out of 97 stories. <<<1 | 2 | 3 | 4
24-May-2012 Supernovas explode in 3-D detail at Oak Ridge National Laboratory
Understanding a Type Ia supernova -- an exploding white dwarf star -- requires supercomputers. A team of astrophysicists and computational scientists is using the power of Oak Ridge National Laboratory's Jaguar to virtually blow up these white dwarfs. In the process the researchers are revealing the secrets of the biggest thermonuclear explosions in the universe and finding the answers needed to measure the size of the universe.
4-Apr-2012 Carbon dioxide caused global warming at ice age's end, pioneering simulation shows
Climate science has an equivalent to the "what came first -- the chicken or the egg?" question: what came first, greenhouse gases or global warming? A multi-institutional team led by researchers at Harvard, Oregon State University, and the University of Wisconsin used a global dataset of paleoclimate records and the Jaguar supercomputer at Oak Ridge National Laboratory to find the answer. The results, published in the April 5 issue of Nature, analyze 15,000 years of climate history.
29-Feb-2012 Climate scientists compute in concert
Researchers at Oak Ridge National Laboratory are sharing computational resources and expertise to improve the detail and performance of a scientific application code that is the product of one of the world's largest collaborations of climate researchers. The Community Earth System Model couples components of atmosphere, land, ocean, and ice to reflect their complex interactions. By continuing to improve science representations and numerical methods in simulations, and exploiting modern computer architectures, researchers expect to further improve the CESM's accuracy in predicting climate changes.
29-Feb-2012 Computation proves predictive capabilities of nuclei through fluorine-14 simulation
Aa team led by Iowa State University physicist James Vary used Oak Ridge Leadership Computing Facility and Argonne Leadership Computing Facility resources to predict the behavior of fluorine-14, a relatively unknown isotope. It published its predictions in Physical Review C in February 2010. Six months later, a group of researchers at Texas A&M University's Cyclotron Institute performed an experiment producing fluorine-14, and the results nearly mirrored those of Vary's group.
8-Feb-2012 Computer scientists collect computing tools for next-generation machines
Researchers using the Oak Ridge Leadership Computing Facility's can foresee substantial changes in scientific application code development. The OLCF's new supercomputer, Titan, will use a hybrid architecture of conventional, multipurpose CPUs and high-performance GPUs. The machine will supplant the OLCF's current fastest supercomputer, Jaguar, a Cray XT5 using an entirely CPU-based platform. Members of the OLCF's Application Performance Tools group understand the challenge. Their goal is to make the transition as smooth as possible.
27-Dec-2011 Materials modeling shows big future for boron nitride nanoribbons
Alejandro Lopez-Bezanilla at Oak Ridge National Laboratory studies a proposed graphene substrate: boron nitride. Graphene, which is carbon in the form of freestanding 1-atom-thick sheets, is a natural for next-generation computer chips, communications equipment, and solar energy devices. Electrons flow through the material at an astonishing 1 million meters per second. To live up to its potential, however, graphene needs support. On its own, its edges wrinkle, tear, or roll up.
5-Dec-2011 Big business and big science partner in computing to speed products to market
Jack Wells spoke about collaborative opportunities in high-performance computing at the Oak Ridge Leadership Computing Facility. He highlighted pathways by which industrial users can gain access to supercomputers. Approximately 60 percent of time available on Jaguar, America's fastest supercomputer, is allocated through the Innovative and Novel Computational Impact on Theory and Experiment program, whereas 30 percent is allocated through the Office of Advanced Scientific Computing Research Leadership Computing Challenge and 10 percent through Director's Discretion.
17-Nov-2011 'Colony' software speeds up high-performance computing processes
As the number of processors continues to increase in leadership-class supercomputers, their ability to perform parallel computation -- doing multiple calculations simultaneously -- becomes increasingly important. The surge in machine size and complexity has led the Oak Ridge Leadership Computing Facility computer scientists to try new and interesting strategies to keep large systems running at the highest efficiency. Their efforts have nearly tripled performance for synchronizing collective operations.
9-Nov-2011 Researchers show how proteins help DNA replicate past a damaged site
A multi-institutional research team led by Ivaylo Ivanov of Georgia State University has employed the Jaguar XT4 supercomputer at Oak Ridge National Laboratory and X-rays a billion times brighter than the sun, produced at Lawrence Berkeley National Laboratory, to illuminate how DNA replication continues past a damaged site so a lesion can be repaired later. The results appear in the Oct. 17, 2011, online issue of Proceedings of the National Academy of Sciences.
15-Sep-2011 Simulating turbulent combustion speeds design of power and propulsion devices
A team led by mechanical engineers Joseph Oefelein and Jacqueline Chen of Sandia National Laboratories simulates turbulent combustion at different scales. Chen and Oefelein were allocated 113 million hours on Oak Ridge Leadership Computing Facility's Jaguar supercomputer in 2008, 2009 and 2010 to simulate autoignition and injection processes with alternative fuels. For 2011 they received 60 million processor hours for high-fidelity simulations of combustion in advanced engines.
19-Aug-2011 Supercomputers and airplanes help model hurricane structure and intensity
Information from major hurricanes such as Katrina is being put to good use by scientists striving to understand how hurricanes intensify. A research team led by Jon Reisner of Los Alamos National Laboratory is employing the Oak Ridge Leadership Computing Facility's Jaguar supercomputer to use data from lightning detectors and even wind instruments mounted on planes flown into the eye of a hurricane to improve atmospheric models. These simulations may lead to more accurate prediction of hurricane intensities.
8-Aug-2011 Breakthrough fusion simulations shed light on plasma confinement
A research team led by William Tang of the Department of Energy's Princeton Plasma Physics Laboratory is developing a clearer picture of plasma confinement properties in an experimental device that will pave the way to future commercial fusion power plants. Over the past three years using resources of the Argonne Leadership Computing Facility and Oak Ridge Leadership Computing Facility, Tang's team has made continual improvements to tools essential for computationally solving fusion problems.
19-Jul-2011 Supercomputers aid in understanding the basic building blocks of nature
A team of scientists collaborating under the leadership of Paul Mackenzie of Fermi National Accelerator Laboratory has been awarded a total of 80 million processor hours at the Oak Ridge Leadership Computing Facility and the Argonne Leadership Computing Facility for quantum chromodynamics research to help develop a unified theory of how the four forces interact. Physicists believe that more fundamental interactions must unite the presently observed forces.
12-Jul-2011 It takes 3 to tango
Researchers who want to understand how and why a nucleus hangs together as it does must take into account the complex interactions known as the three-body force. This conclusion, drawn from simulations on America's most powerful supercomputer, is outlined in the May 20, 2011, edition of Physical Review Letters.
16-Jun-2011 Packing the ions
Drexel University's Yury Gogotsi and colleagues recently needed an atom's-eye view of a promising supercapacitor material to sort out experimental results that were exciting but appeared illogical. That view was provided by a research team led by Oak Ridge National Laboratory computational chemists Bobby Sumpter and Jingsong Huang and computational physicist Vincent Meunier.
1-Jun-2011 Chemistry and materials simulations speed clean energy production and storage
Catalysts are just one area of investigation for a multi-institutional team whose 70 publications in 3 years detail prodigious scientific output from the world's fastest chemistry simulations.
"Our long-term goal is enabling the design of new generations of clean and sustainable technologies to produce, transmit, and store energy," said team leader Robert Harrison, a computational chemist at Oak Ridge National Laboratory.
26-Jan-2011 Neutrons 'go viral' at ORNL
A research team from ORNL and North Carolina State University is using small angle neutron scattering to study how viruses change their structure when they move between different host species. Understanding how a virus reorganizes itself when it goes from a mosquito to a human is critical for the development of medicines that can block the spread of viruses.
29-Nov-2010 Jaguar pounces on child predators
To accelerate the acquisition of information needed to arrest child predators, law enforcement officers have teamed with data analytics experts at Oak Ridge National Laboratory for a project that will use Jaguar, one of the world's fastest supercomputers, to speedily analyze the activities on file-sharing networks that pinpoint porn producers.
19-Nov-2010 Supercomputers assist cleanup of decades-old nuclear waste
A research team led by Peter C. Lichtner of Los Alamos National Laboratory is using the Oak Ridge Leadership Computing Facility's Jaguar supercomputer, located at Oak Ridge National Laboratory, to build a 3-D model of an underground uranium waste plume at the Hanford Site's 300 Area. A better understanding of the underground migration properties of uranium, which has infiltrated the Columbia River, may aid stakeholders in weighing options for contaminant remediation.
5-Aug-2010 Magic secrets
Each year hundreds of visiting scientists conduct research at ORNL's Holifield Radioactive Ion Beam Facility to create and analyze isotopes. These studies give researchers a unique glimpse into the inner workings of atomic nuclei.
16-Sep-2009 Both directions at once
The challenge of controlling climate change is a goal that, to many, appears to be at odds with the equally important goal of energy security. However, the idea that the two goals are somehow mutually exclusive is not one accepted by ORNL energy researcher David Greene. "We don't want to sacrifice one for the other," he says. "We want -- and we believe it possible -- to achieve environmental goals and energy security goals at the same time.
The Department of Energy's Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time.