In the late 1980s, when setting up his first laboratory, an asst. prof. of chemistry at the Univ. of South Carolina had a conversation with a scientist at IBM Yorktown, Avi Aviram, who had recently authored a paper speculating on a new type of perpendicularly shaped molecule that, if artificially created and equipped with active sensing points, could be used as a molecular switch for computing.
By using optical techniques, researchers in...
With the help of the x-ray light source PETRA III...
The Q-factor is a dimensionless parameter that...
As NASA prepares to launch a new Martian probe, a scientist at Florida State Univ.’s MagLab has uncovered what may be the first recognized example of ancient Martian crust. Professor Munir Humayun’s groundbreaking discoveries are based on an analysis of a 4.4 billion-year-old Martian meteorite that was unearthed by Bedouin tribesmen in the Sahara desert.
Superfluidity refers to a state in which matter behaves like a liquid with zero viscosity. With a few exceptions, superfluidity has generally been regarded as a macroscopic phenomenon, resulting from “bulky” collections of particles rather than individual atoms. Scientists in Switzerland have now provided the first experimental evidence of superfluidity at the nanoscale, shedding light on the fundamental basis of the phenomenon.
Until recently, the preparation of phosphor materials, key components in white LED lighting, was more an art than a science. It has been based on finding crystal structures that act as hosts to activator ions, which convert the higher-energy blue light to lower-energy yellow/orange light. By determining simple guidelines, researchers have recently made it possible to optimize phosphors allowing for brighter, more efficient lights.
The effort to better understand nanoscale properties has produced large-scale government and industrial research organizations, such as the National Nanotechnology Initiative (NNI) and the Nanoelectronics Research Initiative (NRI). These efforts, each funded in the billion-dollar range, depend on the ability of researchers from around the world to effectively use the analytical tools.
When it comes to detectors for dangerous chemicals, toxins or nefarious germs, smaller and faster is better. But size and speed must still allow for accuracy, especially when measurements by different instruments must give the same result. The recent publication of a new NIST standard provides confidence that results from handheld chemical detectors can be compared, apples-to-apples.
Of all the standard units currently in use around the world, the kilogram is the only one that still relies on a physical object for its definition. But revising this outdated definition will require precise vacuum-based measurements that researchers are not yet able to make. A new system is in development that would allow a direct comparison of an object being weighed in a vacuum to one outside a vacuum.
Scientists have used the powerful x-ray laser at the SLAC National Accelerator Laboratory to create movies detailing trillionths-of-a-second changes in the arrangement of copper atoms after an extreme shock. The study pinpointed the precise breaking point when the extreme pressures began to permanently deform the copper structure, or lattice, so it could no longer bounce back to its original shape.
Vanadium dioxide is one of the few known materials that acts like an insulator at low temperatures but like a metal at warmer temperatures starting around 67 C. This temperature-driven metal-insulator transition, the origin of which is still intensely debated, could be induced by the application of an external electric field. Beamline studies at the Advanced Light Source has shed some light on this potential avenue for faster electronics.
Earth’s most eminent emissary to Mars has just proven that those rare Martian visitors that sometimes drop in on Earth really are from the Red Planet. A key new measurement of Mars’ atmosphere by NASA’s Curiosity rover provides the most definitive evidence yet of the origins of Mars meteorites while at the same time providing a way to rule out Martian origins of other meteorites.
Micromachines operate under very different conditions than their macroscale cousins. The high surface-area-to-mass ratio of tiny motors means they require a constant driving force to keep them going. In the past, researchers have relied on asymmetric chemical reactions on the surface of the motors to supply the force. Researchers in Japan have now discovered, however, that two-sided materials aren't necessary to make micromotors move.
During evolution, many plants and organisms have developed mushroom-shaped adhesive structures and organs that allow them to climb walls and grip surfaces. Through observations of these microstructures at speeds of up to 180,000 frames per second, scientists have discovered why the specific shape is advantageous for adhesion.
A research team that includes a physics prof. at Indiana Univ.-Purdue Univ. Indianapolis has recorded a drastically reduced measurement of the Casimir effect, a fundamental quantum phenomenon experienced between two neutral bodies that exist in a vacuum. The experiment used nanostructured metallic plates to suppress the force at a much lower rate than ever recorded previously.
A new study has found that “waviness” in forests of vertically-aligned carbon nanotubes dramatically reduces their stiffness, answering a long-standing question surrounding the tiny structures. Instead of being a detriment, the waviness may make the nanotube arrays more compliant and therefore useful as thermal interface material for conducting heat away from future high-powered integrated circuits.
Water pours into a cup at about the same rate regardless of whether the water bottle is made of glass or plastic. But at nanometer-size scales, material type does make a significant difference. A new study shows that in nanoscopic channels, the effective viscosity of water in channels made of glass can be twice as high as water in plastic channels, potentially affecting a variety of research approaches.
A study of data from hundreds of soil samples taken around six old water tower sites in southern Rhode Island finds that even when lead levels on the surface are low, concentrations can sometimes be greater at depths down to a foot. The findings inform efforts to assess the effect of lead paint from old water towers on surrounding properties.
Researchers at the Virginia Tech Carilion Research Institute have reported the first experimental evidence that supports the theory that a soccer ball-shaped nanoparticle, commonly called a buckyball, is the result of a breakdown of larger structures rather than being built atom-by-atom from the ground up.
More than one billion people worldwide rely on fish as an important source of animal protein, consuming low levels of methylmercury. Methylmercury compounds specifically target the central nervous system, but now researchers have combined synchrotron x-rays with methylmercury-poisoned zebrafish larvae to learn that they may also affect our vision.
Kerogen is a mixture of organic chemical compounds in sedimentary rocks that is a key intermediate of oil and natural gas. After five years of research, researchers in China have developed a terahertz time-domain spectroscopy method that effectively detects the generation of oil and gas from kerogen without contact or destruction of the sample material.
Biological cells are surrounded by a membrane, which researchers in Denmark have can contain beautiful, mysterious patterns. Formed by highly organized lipids, the patterns vary according to conditions such as temperature and the type of lipid molecules. Extremely difficult to detect, these patterns have as yet no known biological function.
Composed of a very little number of atoms, nanomachines offer the promise of a revolution in manufacturing and civilization. Researchers around the world look at various molecules trying to put them to work. But recent measurements in Poland using a new technique for estimating power generated by motors of single molecule in size reveal that power of such motors is considerably less than expected by developers.
Obtaining surface maps of elastic modulus and hardness has been a persistent goal of the nanoindentation community. One solution is to infer properties from an atomic force microscopy scan of the surface, called modulus mapping; but the technique has subtle but significant limitations. Agilent Technologies’ Express Test option offers users of the Agilent Nano Indenter G200 a comprehensive solution for mechanical properties mapping, while also delivering unprecedented testing speed.
Graphene was originally made using a method called “exfoliation” which involves pulling graphite apart. Growing graphene epitaxially is more suitable for mass production, but the industry still lacks fast, inexpensive measurement tools to guarantee product quality. A new technique developed in the U.K. is based on optical microscopy and can be used to understand the effect of a silicon carbide substrate on the quality of the graphene layer.
Over the last few years, the use of nanomaterials for water treatment, food packaging, pesticides, cosmetics and other industries has increased. A growing concern is that these particles could pose a potential health risk has prompted a large number of studies, including recent work at the Univ. of Missouri that showed the retention of silver nanoparticles in pear skin, even after repeated washing.
It is well known to scientists that the three common phases of water (ice, liquid and vapor) can exist stably together only at a particular temperature and pressure, called the triple point. Scientists now have made the first-ever accurate determination of a solid-state triple point in a substance called vanadium dioxide, which is known for switching rapidly from an electrical insulator to a conductor.
Researchers at the Carnegie Institution and the Univ. of Illinois have for the first time been able to experimentally simulate the pressure conditions in the Earth’s mantle to measure thermal conductivity. A new technique using the mantle material magnesium oxide allowed the team to discover that heat transfer is actually lower than what has been claimed by other predictions and amounts to about 60% used by civilization today.
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