Wall turbulence develops when fluids—liquid or gas—flow past solid surfaces at anything but the slowest flow rates. Progress in understanding and controlling wall turbulence has been somewhat incremental because of the massive range of scales of motion involved, but recently engineers in the U.S. and the U.K. have developed a new and improved way of looking at the composition of turbulence near walls.
In the runaway greenhouse stage, a planet absorbs more solar energy than it can give off to retain equilibrium. As a result, the world overheats, boiling its oceans and filling its atmosphere with steam, which leaves the planet glowing-hot and forever uninhabitable, as Venus is now. Recent research shows this scenario might be more easily reached than previously thought.
In an epidemic or a bioterrorist attack, the response of government officials could range from a drastic restriction of mobility to moderate travel restrictions in some areas or simple suggestions that people remain at home. Deciding to institute any measure would require officials to weigh the costs and benefits of action, but at present there’s little data to guide them. However, a new study comparing contagion rates may come in handy.
The rate at which carbon dioxide is released from permafrost is poorly documented, and is a crucial uncertainty in current climate models. New findings by environmental scientists at the Univ. of Copenhagen, Denmark, document that permafrost during thawing may result in a substantial release of carbon dioxide into the atmosphere and that the future water content in the soil is crucial to predict the effect of permafrost thawing.
The Powerwall Theater (PWT) at Los Alamos National Laboratory is an innovative facility that enables researchers to view the complex models and simulations they have created using some of the world’s fastest supercomputers. Recently, PWT was upgraded with 40 double-stacked Christie Mirage 3-D LED projectors that will provide seamless, integrated 3-D visualization.
Taking advantage of the power of cloud computing, researchers have simulated almost every important configuration of cloth. Though computing all the ways cloth can move would be impossible, the 4,554 CPU hours and 33 GB of data generated represents an ambitious effort to improve graphics for next-generation computer games.
Researchers at Brown Univ. have shown that some Martian valleys appear to have been caused by runoff from orographic precipitation—moisture carried part of the way up a mountain and deposited on the slopes. The new findings are the most detailed evidence yet of an orographic effect on ancient Mars.
The principle of proton conduction in water has been known for 200 years and is named after its discoverer, Theodor Grotthuss. Using theoretical calculations, researchers have now been able to analyze this mechanism in more detail and have shown that the currently accepted picture of proton diffusion, which has been compared to a “bucket line”, may need to be revised.
In events that could exacerbate sea level rise over the coming decades, stretches of ice on the coasts of Antarctica and Greenland are at risk of rapidly cracking apart and falling into the ocean, according to new iceberg calving simulations from the Univ. of Michigan.
Earlier this year, MIT researchers developed a way to edit the genomes of living cells. Now, the researchers have discovered key factors that influence the accuracy of the system. With this technology, scientists can deliver or disrupt multiple genes at once, raising the possibility of treating human disease by targeting malfunctioning genes. To help with that process, the team has now created a computer model.
Scientists in the new but fast-growing field of computational genomics are facing a dilemma. These researchers have begun to assemble the chemical blueprints of the DNA found in humans, animals, plants and microbes. But a flood of unassembled genetic data is being produced much faster than current computers can turn it into useful information, two scholars in the field are warning.
The length of the satellite record for the Greenland and Antarctic ice sheets is currently too short to tell if the recently reported speed-up of ice loss will be sustained in the future or if it results from natural processes, according to a new study. Sheets are losing are about 300 billion tons of ice each year, but no consensus has emerged about the cause of this recent increase in mass loss.
The Ranger supercomputer in Texas has recently been used to determine how to sculpt fluid flows by precisely placing tiny pillars in microfluidic channels. By altering fluid speed and stacking pillars, a wide arrays of controlled flows can be achieved. This could be a boon for clinicians who would like to separate white blood cells in a sample, or more quickly perform lab-on-a-chip-type operations.
Despite warnings to the contrary, many people continue to operate portable generators indoors or close to open windows, resulting in more than 500 deaths since 2005. And each year, more than 20,000 people visit the emergency room and more than 4,000 are hospitalized due to exposure to toxic levels of carbon monoxide. A new computer modeling study scrutinizes the deadly relationship between carbon monoxide emissions and occupant exposure.
The Consortium for Advanced Simulation of Light Water Reactors (CASL) announced that its scientists have successfully completed the first full-scale simulation of an operating nuclear reactor. CASL is modeling nuclear reactors on supercomputers to help researchers better understand reactor performance, with the goal of ultimately increasing power output, extending reactor life and reducing waste.
Studies have long predicted that plants would begin to use water more efficiently, that is, lose less water during photosynthesis, as atmospheric carbon dioxide levels rose. However, an international research team doing work at the Harvard Forest Long-Term Ecological Research site has found that forests across the globe are losing less water than expected and becoming even more efficient at using it for growth.
There are several ways to “trap” a beam of light. But now researchers at the Massachusetts Institute of Technology have discovered a new method to trap light that could find a wide variety of applications. The new system, devised through computer modeling and then demonstrated experimentally, pits light waves against light waves.
In spite of the tremendous progress made over the last 80 years, important gaps in our understanding of the hydrogen phase diagram remain, with arguably the most challenging issue being the solid-to-liquid melting transition at ultra-high pressures. A new study in the U.K. has looked at the melting of hydrogen by computer simulation, for the first time taking the quantum motion of the protons into account explicitly.
Knowing virtually everything about how the body’s cells make transitions from one state to another would be a major jump forward in understanding the basics of what drives biological processes. An interdisciplinary team of researchers report on taking at least a step toward better comprehension of the fundamentals of “cell fate determination”.
According to NASA, there are more than 21,000 pieces of “space junk roughly the size of a baseball in orbit, and about 500,000 pieces that are golf ball-sized. These pieces can be dangerous, which is why researchers at Texas Advanced Computing Center’s supercomputers are simulating orbital debris impacts on spacecraft and fragment impacts on body armor to help NASA design better shielding.
The National Institute of Standards and Technology this week announced that it plans to establish a new Advanced Materials Center of Excellence to facilitate collaborations between NIST and researchers from academia and industry on advanced materials development. Fund at about $25 million over five years, the center will emphasize innovations in measurement technology, modeling, simulation, and data and informatics tools
How do fish swim? It is a simple question, but there is no simple answer. Researchers at Northwestern Univ. have revealed some of the mechanical properties that allow fish to perform their complex movements. Their findings could provide insights in evolutionary biology and lead to an understanding of the neural control of movement and development of bio-inspired underwater vehicles.
After analyzing genomic sequencing data from the Human Genome Project and other sources, scientists in Maryland have found evidence that lateral gene transfer is possible from bacteria to the cells of the human body, known as human somatic cells. They also found that bacterial DNA was more likely to integrate in the genome in tumor samples than in normal, healthy somatic cells.
JMAG is a powerful finite element analysis (FEA) tool that allows engineers to develop, analyze, and fine-tune electric motors and generators, taking into account such diverse factors as thermal, structural, and vibration issues. This week, Maplesoft has launched a new product that allows users to combine JMAG with the advanced physical modeling approach of MapleSim. This allows engineers to produce high-fidelity system models.
Rice Univ. researchers have for the first time detailed the molecular mechanism that makes a particular combination of cement and polymer glue so tough. The theoretical research led to a fine picture of how hydrogen bonds control the properties of hybrid organic-inorganic materials. The finding has implications for understanding the interface bonding that is often a roadblock to improved composite properties.