Green supercomputing paves the way for sharing scientific research and collaboration

Energy efficiency ranks second when compared to renewable power generation as a solution to climate change, but for Phillip Dickens, a professor at the University of Maine, it is first in the world of supercomputing.

With the evolution of supercomputers over the last few years, speed, memory and capability have increased tremendously. The early models of computers were enormous in size, often filling a large room. One of the challenges of having a computer this size was the large amount of heat that it generated and how to keep it cool. Two dominant factors that have influenced supercomputer design are Moore's Law and economies of scale.

Today, a modern desktop computer running at 2.66 GHz is more powerful than a 10-year-old supercomputer, and costs considerably less.

In addition, parallelization allows for several smaller parts to work simultaneously and limits the amount of information that can be transferred between processing units. Clusters of computers can also be programmed to function as a single large computer. There are many possibilities that can maximize the energy efficiency of the hardware and software of supercomputers.

Dickens received a two year, $200,000 National Science Foundation (NSF) research grant that funded the development of a scientific grid portal in Maine and the purchase of an energy efficient supercomputer. The purpose of the grid-portal is to make research from the University of Maine Institute of Climate Modeling available to top research scientists down to school age children.

Results of widely used ice sheet models, tools for climate change research, prototype versions of object based caching system, real-time animations and video are just a few of the applications that will be available. In addition, the grid portal will provide the larger community with the computing power, storage capacity, and rendering engine to execute very high-resolution models and receive animations and other visual information in real time.

In a demonstration of energy efficiency, the University of Maine, Department of Computer Science, unveiled the first cyclist-powered "green" supercomputer. Powered by 10 cyclists, the eco-friendly SiCortex SC648 supercomputer successfully ran a program demonstrating glacial melting for 20 minutes.

"The fact that a computer can be powered by a team of cyclists underscores how efficient computers have become," said University of Maine professor George Markowsky.

Computer scientists are continually searching for new ways to reduce the amount of energy it takes to operate computer systems. The SiCortex SC648 is the first of two low power HPC systems to be developed in the state of Maine. It combines desktop accessibility with low cooling requirements of a standard PC, but has the speed and power for high-productivity computing. The SC648 can develop, distribute, run multiple applications and uses 1000 watts of power. In addition to the SC648, the University of Maine has also invested in the SiCortex SC072. It provides answers to complex scientific computing challenges as quickly as conventional cluster computers, but at the fraction of the energy requirement using 300 watts of power. Both computer systems will power the University of Maine Scientific Grid Portal and provide access to computing resources, scientific applications and research animations.

"The computer industry is still in the early phase of realizing the importance of power consumption. Most computer users today don't think about energy and infrastructure costs when making a buying decision. With climate change looming, energy costs skyrocketing and the economy stumbling, power requirements are being thrust into the foreground," said James Bailey, marketing director of SiCortex.

Although Dickens is at the forefront of "green" supercomputing, his desire exceeds the current eco-friendly capabilities. "We are still in the beginning phase. It would have been nice to show multiple displays, all executing different phases, showing different processes. We have one application now and we are looking to get more because there is a lot of demand," he said.

The South Pole: A Premier Observatory

Astronomers work at the South Pole to take advantage of excellent viewing conditions. Cold, dry Antarctica will allow SPT to more easily detect the cosmic microwave background (CMB) radiation, the afterglow of the big bang, with minimal interference from water vapor. On the electromagnetic spectrum, the CMB falls somewhere between heat radiation and radio waves.

The CMB is largely uniform, but it contains tiny ripples of varying density and temperature. These ripples reflect the seeds that, through gravitational attraction, grew into the galaxies and galaxy clusters visible to astronomers today. The SPT's first key science project will be to study small variations in the CMB to determine if dark energy began to affect the formation of galaxy clusters by fighting against gravity over the past few billion years.

Galaxy clusters are groups of galaxies, the largest celestial bodies that gravity can hold together. "Our galaxy, the Milky Way, is in one of these clusters," Meyer said. "And these clusters of galaxies actually change with time."

The CMB allows astronomers to take snapshots of the infant universe, when it was only 400,000 years old. No stars or galaxies had yet formed. If dark energy changed the way the universe expanded, it would have left its "fingerprints" in the way it forced galaxies apart over the deep history of time. Different causes would produce a different pattern in the formation of galaxy clusters.

According to one idea, dark energy could be Albert Einstein's cosmological constant: a steady force of nature operating at all times and in all places. Einstein introduced the cosmological constant into his theory of general relativity to accommodate a stationary universe, the dominant idea of the day. If Einstein's idea is correct, scientists will find that dark energy was much less influential in the universe 5 billion years ago than it is today.

"Clusters weren't around in the early universe. They took a long time to evolve," Carlstrom said.

Another version of the dark energy theory, called quintessence, suggests a force that varies in time and space. Some scientists even suggest there is no dark energy at all, and that gravity merely breaks down on vast intergalactic scales.

To pinpoint when dark energy became important, SPT will use a phenomenon called the Sunyaev-Zeldovich effect, which distorts the CMB as it passes through the hot gas of intervening galaxy clusters. As the microwaves interact with gas in the clusters, some of the microwaves get kicked into a higher frequency. SPT will measure the slight temperature difference associated with the frequency change and produce an image of the gas in the cluster.

SPT can scan large regions of the sky quickly. Scientists expect it to detect thousands, or even tens of thousands, of galaxy clusters within a few years. "To get a meaningful constraint on dark energy through measuring galaxy clusters, you need something like this South Pole Telescope," Carlstrom said. "The cluster SZ [Sunyaev-Zeldovich] signals cover small patches in the sky relative to the intrinsic variations in the cosmic microwave background. To get the necessary resolution, you need a big telescope. Now we have one."

Senior members of the SPT team include William Holzapfel, Adrian Lee and Helmuth Spieler from the University of California at Berkeley and the Lawrence Berkeley National Laborator; Joe Mohr, from the University of Illinois at Urbana-Champaign; John Ruhl from Case Western Reserve University; Antony Stark, from the Harvard-Smithsonian Astrophysical Observatory; Matt Dobbs from McGill University; and Erik Leitch of NASA's Jet Propulsion Laboratory.

SLIPPERY ELM - Ulmus rubra, Muhl

EXCEPT FOR SCATTERED counties in the Ozarks, slippery elm is found in almost every county in the state. Like American elm, slippery elm is a water-loving tree and grows best on moist, rich soils on lowers slopes, stream banks, river terraces and bottomlands.

The leaf is alternate, simple, with a coarsely double saw-toothed edge. It ranges from five to seven inches long and two to three inches wide. It is egg-shaped with the broadest part above the middle and the base slightly uneven. The tip is drawn out to a long, narrow point. The upper surface of the leaf is dark green and very rough while the under-surface is lighter and hairy. This rough leaf distinguishes it from the American elm which has a smooth leaf.

The fruit occurs in clusters and each seed and stem is 3/4 inch long. A single seed is surrounded by a thin, papery wing, smooth around the edge. It is common to see small drifts of elm seeds along sidewalks in metropolitan areas after a heavy rain.

Twigs are slender to moderately stout. They are gray and very rough to the touch. The buds are egg-shaped, pointed and covered with dark chestnut-brown hairs. The bark on older trees is reddish-brown. It is furrowed with platy or scaly ridges and the inner bark contains a sticky sap once used as a medicine by Indians and pioneers.

Like American elm, the seeds, buds, and leaves of slippery elm furnish food for the gray and fox squirrel and deer.The wood of slippery elm is heavy, tough, and strong. Of all the elms, it has the best and most durable lumber. It is used in the manufacture of furniture and for many other uses. Because of intertwined fibers, it is hard to split with an axe. Unprotected piles of lumber will twist and warp.

Growing along with slippery elm may be American elm, black cherry, white ash, blue ash, black walnut, bitternut hickory, bur oak, basswood, silver maple, and white oak. This elm is also susceptible to Dutch elm disease and many leaf-chewing insects.

Fresh or Frozen, Defender Is a Good Potato

Long, white-skinned potatoes in the produce section of your supermarket might be "Defender"—the only commercially grown potato in the United States today with tubers and leaves that fend off late blight disease. Worldwide, late blight is generally regarded as one of the worst diseases of potatoes.

Besides starring as a fresh-market potato, Defender also can be processed into frozen products. ARS scientists in the Small Grains and Potato Research Unit , Aberdeen, Idaho, and the Vegetable and Forage Crop Research Unit, Prosser, Wash., worked with university colleagues to in Idaho, Oregon and Washington develop this superior spud. They put it through more than a decade of rigorous outdoor tests before making it available to growers, processors, potato-seed companies and others last year.

The plant's natural resistance to late blight allows growers to use either no fungicides—or much smaller amounts—to control the disease. This feature makes the potato ideal for conventional and organic farms alike.