Plasmonic nanostructures are of great current interest as chemical sensors or imaging agents because they can detect the emission of light at a different wavelength than the excitation light. Researchers have struggled with how to interpret this resonant secondary light emission. Recent work that models the emission as Raman scattering from electron-hole pairs, however, has shown a way to predict emission outcome.
New model calculations indicate that the extreme density of the base of the thickened primary crust caused it to subside vertically, or “drip”, into Earth's mantle during the Archean eon, which began about 4 billion years ago. In contrast, the movements of today's tectonic plates involve largely lateral movements with oceanic lithosphere recycled in subduction zones.
A group of researchers at Carnegie Mellon Univ. is banking on the efficiency of an environmentally friendly alternative to large hydroelectric operations. Known as hydrokinetic or run-of-the-river power extraction, the new method harvests a small portion of kinetic energy in the river at multiple locations. They are building multi-scale hierarchical models for analyzing large-scale river networks, hydropower project placement, and control.
Physicists in Germany have developed a “planet-satellite model” to precisely connect and arrange nanoparticles in 3-D structures. Inspired by the photosystems of plants and algae, these artificial nanoassemblies of DNA strands might in the future serve to collect and convert energy.
Computational work conducted at Northwestern Univ. has led to a new mathematical theory for understanding the global spread of epidemics. The resulting insights could not only help identify an outbreak’s origin but could also significantly improve the ability to forecast the global pathways through which a disease might spread.
Jupiter’s moon Europa features an intricate network of cracks in its icy surface. This unusual pattern is particularly pronounced around the equator. Scientists performing modeling studies on the potential marine currents below this ice layer have discovered that, near Europa’s equator, warmer water rises from deep within the moon.
To learn new motor skills, the brain must be plastic: able to rapidly change the strengths of connections between neurons, forming new patterns that accomplish a particular task. However, if the brain were too plastic, previously learned skills would be lost too easily. A new computational model explains how the brain maintains the balance between plasticity and stability, and how it can learn similar tasks without interference.
In a new effort to understand magnetism, a group of Hamburg Centre for Ultrafast Imaging researchers created “mimic” magnets by controlling quantum matter waves made of rubidium atoms. Under well-defined conditions made possible with the help of supercomputers, these artificially created magnets can be studied with clarity and then give a fresh perspective on long-standing riddles.
The research team was inspired by biological processes in species such as amphibians, which can regenerate severed limbs, engineers in Pittsburgh have developed computational models to design a new polymer gel that would enable complex materials to regenerate bulk sections of severed material using nanorods.
A new study reveals how pollution causes thunderstorms to leave behind larger, deeper, longer lasting clouds. Appearing in the Proceedings of the National Academy of Sciences, the results solve a long-standing debate and reveal how pollution plays into climate warming. The work can also provide a gauge for the accuracy of weather and climate models.
Researchers at Los Alamos National Laboratory are investigating the complex relationships between the spread of the HIV virus in a population (epidemiology) and the actual, rapid evolution of the virus (phylogenetics) within each patient’s body. The team models the uninfected population using traditional differential equations on the computer; this is done for computational speed, because an agent-based component is much more demanding.
“Function follows form” might have been written to describe proteins, as the M. C. Escher-esque folds and twists of nature’s workhorse biomolecules enables each to carry out its specific responsibilities. X-ray protein crystallography determines protein structures by creating a diffraction pattern of dots that can be reconstructed by computer into a 3-D model.
One of the world’s largest dinosaurs has been digitally reconstructed by experts from The Univ. of Manchester allowing it to take its first steps in over 94 million years. The Manchester team, working with scientists in Argentina, were able to laser scan a 40-m-long skeleton of the vast Cretaceous Argentinosaurus dinosaur. Then using an advanced computer modeling technique they recreated its walking and running movements.
In a pair of studies that exploit the genetic sequencing of the “missing link” cold virus, rhinovirus C, scientists at the Univ. of Wisconsin-Madison have constructed a 3-D model of the pathogen that shows why there is no cure yet for the common cold. The new cold virus model was built in silico, drawing on advanced bioinformatics and the genetic sequences of 500 rhinovirus C genomes, which provided 3-D coordinates of the viral capsid.
Scientists in Germany have developed a mathematical model for a type of microscopic test lab that could provide new and deeper insight into the world of quantum particles. The new test system will enable the simultaneous study of one hundred light quanta, or photons, and their quantum entanglements. This is a far greater number than was previously possible.
A new physics model developed at Rensselaer Polytechnic Institute shows that changing air flows can transfer energy to wind turbines from both above and below the blades. According to the researchers, many wind turbine array studies overlook the fact that important airflow changes occur inside the array.
A new study set out to use numerical simulations to validate previous theoretical predictions describing materials exhibiting so-called antiferromagneting characteristics. A recently discovered theory shows that the ordering temperature depends on two factors—namely the spin-wave velocity and the staggered magnetization. The simulations match these theoretical predictions.
A research team including a Penn State chemical engineer was recently awarded a $3.9 million National Science Foundation grant to understand how blue-green algae convert nitrogen into oxygen. The objective is to learn how to "transplant" the nitrogen fixing capability of one species to another.
Around 3% of all plants use an advanced form of photosynthesis, which allows them to capture more carbon dioxide, use less water, and grow more rapidly. This phenomenon had been a mystery, but researchers have used a mathematical analysis to uncover a number of tiny changes in the plants' physiology that allow them to grow more quickly, using a third as much water as other plants and capturing around 13 times more carbon dioxide.
Enhanced growth of Earth's leafy greens during the 20th century has significantly slowed the planet's transition to being red-hot, according to the first study to specify the extent to which plants have prevented climate change since pre-industrial times. Researchers have found that land ecosystems have kept the planet cooler by absorbing billions of tons of carbon, especially during the past 60 years.
Three U.S.-based scientists won the 2013 Nobel Prize in chemistry for developing powerful computer models that others can use to understand complex chemical interactions and create new drugs. Research in the 1970s by Martin Karplus, Michael Levitt and Arieh Warshel has helped scientists develop programs that unveil chemical processes such as the purification of exhaust fume or photosynthesis, the Royal Swedish Academy of Sciences said.
A tag team of two bacteria, one of them genetically modified, has a good chance to reduce or even eliminate the deadly disease African trypanosomiasis, or sleeping sickness, researchers at Oregon State Univ. conclude in a recent mathematical modeling study. African trypanosomiasis, caused by a parasite carried by the tsetse fly, infects 30,000 people in sub-Saharan Africa each year and is almost always fatal without treatment.
Electrical currents born from thunderstorms are able to flow through the atmosphere and around the globe, causing a detectable electrification of the air even in places with no thunderstorm activity. But a good understanding of atmospheric conductivity has eluded scientists. Now, a research team in Colorado has developed a global electric circuit model by adding an additional layer to a climate model.
Since the discovery of the Van Allen radiation belts in 1958, space scientists have believed these belts encircling the Earth consist of two doughnut-shaped rings of highly charged particles. In February of 2013, a team of scientists reported the surprising discovery of a previously unknown third radiation ring. In new research, scientists have successfully modeled and explained the unprecedented behavior of this third ring.
Human influences have directly impacted the latitude/altitude pattern of atmospheric temperature. That is the conclusion of a new report by scientists from Lawrence Livermore National Laboratory and six other scientific institutions. The research compares multiple satellite records of atmospheric temperature change with results from a large, multimodel archive of simulations.