If the chemical bonds that hold together the constituent atoms of a molecule could be tuned to become stronger or weaker, certain chemical properties of that molecule might be controlled to great advantage for applications in energy and catalysis. Researchers were able to accomplish this feat by using an applied voltage and electric current to tune the strength of chemical bonds in fullerene or buckyball molecules.
Flexible, layered materials textured with nanoscale wrinkles could provide a new way of controlling the wavelengths and distribution of waves, whether of sound or light. The new method could eventually find applications from nondestructive testing of materials to sound suppression, and could also provide new insights into soft biological systems and possibly lead to new diagnostic tools.
Silicon-based electronics have physical limits that slow and may eventually halt the miniaturization of electronic devices. One of the possible solutions is to use molecules as circuits, but their poor conduction capabilities make them unlikely candidates. Researchers in Italy says, however, that the Kondo effect, in which molecules behave like magnetic impurities, could offer a solution.
Scientists have wondered why polar bear fur is much more efficient at insulation than what we can develop for our housing. Now, a team has calculated that hairs, due to an unexpected optical mechanism, reflect infrared light and may contribute significant insulating power to the exceptionally warm winter coats of polar bears and other animals.
A breakthrough for the field of spintronics, a new type of technology which it is widely believed could be the basis of a future revolution in computing, has been announced by scientists in the U.K. The new study breaks new ground by showing, for the first time, that the natural spin of electrons can be manipulated, and more importantly detected, within the current flowing from a superconductor.
Many of the most interesting things in nature, from spectacular lightning strikes to the subtlety of life itself, are transient. To discover the secrets of transient, or far from equilibrium, states, physicists need simple yet appealing laboratory systems. Researchers have managed to create just such a system in the magnetic material known as "spin ice".
Until recently, measuring a 27-dimensional quantum state would have been a time-consuming, multistage process using a technique called quantum tomography, which is similar to creating a 3-D image from many 2-D ones. Researchers at the Univ. of Rochester have been able to apply a recently developed, alternative method called direct measurement to do this in a single experiment with no post-processing.
A new approach to harvesting solar energy, developed by Massachusetts Institute of Technology researchers, could improve efficiency by using sunlight to heat a high-temperature material whose infrared radiation would then be collected by a conventional photovoltaic cell. This technique could also make it easier to store the energy for later use, the researchers say.
The most efficient way to convert light into different wavelengths for use in spectroscopy or laser applications is to use nonlinear optical crystals, but these tend to suffer crystal damage at high laser intensities. Oleg Louchev of the RIKEN Center in Japan and colleagues have discovered that such crystal damage arises from small localized temperature rises due to photon absorption and electric field effects within the crystal.
A carbon nanotube (CNT) sponge capable of soaking up water contaminants more than three times more efficiently than previous efforts has been presented in a new study. The CNT sponges, uniquely doped with sulfur, also demonstrated a high capacity to absorb oil, potentially opening up the possibility of using the material in industrial accidents and oil spill cleanups.
Using the interaction between light and charge fluctuations in metal nanostuctures called plasmons, a Univ. of Arkansas physicist and his collaborators have demonstrated the capability of measuring temperature changes in very small 3-D regions of space. In the experiments the team fabricated plasmonic nanostructures with electron beam lithography and precisely focused a laser on to a gold nanowire with a scanning optical setup.
A new model by a team of researchers may shed new understanding on the phenomenon known as discontinuous shear thickening (DST), in which the resistance to stirring takes a sudden jump. Easily observed in a “kitchen experiment” by mixing together equal amounts of cornstarch and water, DST occurs because concentrated suspensions of hard particles in a liquid respond differently than normal fluids to shear forces.
Rice Univ. scientists have found they can control the bonds between atoms in a molecule. The molecule in question is carbon-60, also known as the buckminsterfullerene and the buckyball, discovered at Rice in 1985. The scientists found that it’s possible to soften the bonds between atoms by applying a voltage and running an electric current through a single buckyball.
Computer scientist Yi-Kai Liu at NIST has devised a way to make a security device that has proved notoriously difficult to build: a "one-shot" memory unit, whose contents can be read only a single time. The innovation, which uses qubits and conjugate coding, shows in theory how the laws of quantum physics could allow for the construction of such memory devices.
For decades, increasing amounts of data have been successfully stored on media with ever-higher densities. Now, an international team has discovered a physical phenomenon that could prove suitable for use in further data aggregation. Researchers found that domain walls, which separate areas in certain crystalline materials, display a polarization, potentially allowing information to be stored in the tiniest of spaces.
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.
A team at the Laboratory for Attosecond Physics in Germany has constructed a detector which provides a detailed picture of the waveforms of femtosecond laser pulses. Knowledge of the exact waveform of these pulses enables scientists to reproducibly generate light flashes that are a thousand times shorter, just attoseconds, and can be used to study ultrafast processes at the molecular and atomic levels.
Inventor Nikola Tesla imagined the technology to transmit energy through thin air almost a century ago, but experimental attempts at the feat have so far resulted in cumbersome devices that only work over very small distances. But now, Duke Univ. researchers have demonstrated the feasibility of wireless power transfer using low-frequency magnetic fields over distances much larger than the size of the transmitter and receiver.
Cilia are one of nature’s great multipurpose tools. The tiny, hair-like fibers protrude from cell membranes and perform all kinds of tasks in all kinds of creatures, from helping clear debris from human lungs to enabling single-celled organisms to swim. Now, physicists from Brown Univ. have discovered something that could help scientists understand how cilia have been adapted for so many varied tasks.
According to recent research that shows the first unambiguous theoretical evidence of quantum effects in photosynthesis, light-gathering macromolecules in plant cells transfer energy by taking advantage of molecular vibrations whose physical descriptions have no equivalents in classical physics.
A surprising effect created by a 19th-century device called a Helmholtz coil offers clues about how to achieve controlled nuclear fusion at Sandia National Laboratories’ Z machine. A Helmholtz coil produces a magnetic field when electrified. In recent experiments, two Helmholtz coils, installed to provide a secondary magnetic field to Z’s huge one, unexpectedly altered and slowed the growth of the magneto-Rayleigh-Taylor instabilities.
To understand how to design better thermoelectric materials, researchers are using neutron scattering at the Spallation Neutron Source and the High Flux Isotope Reactor at Oak Ridge National Laboratory to study how silver antimony telluride is able to effectively prevent heat from propagating through it on the microscopic level.
Images released by NASA on Tuesday show galaxies that are 20 times fainter than those pictured before. They are from a new campaign to have the 23-year-old Hubble Space Telescope gaze much earlier and farther away than it was designed to see. The spacecraft is now looking within 500 million years after the Big Bang.
A newly discovered system of two white dwarf stars and a superdense pulsar is packed within a space smaller than the Earth’s orbit around the sun. The finding is scientists’ best opportunity yet to discover a violation of a key concept in Albert Einstein’s theory of General Relativity: the strong equivalence principle, which states that the effect of gravity on a body does not depend on the nature or internal structure of that body.
By effectively “exploding” instead of erupting, supervolcanos release tremendous energy. Because none are currently “live”, how supervolcanos become active has remained a mystery. Geologists have now demonstrated that the pressure generated through the difference in density between magma and the surrounding rock alone can be sufficient to cause one of these geological giants to erupt.