Turbine manufacturers have employed special nickel-based high-performance “superalloys” for decades as a way to guarantee turbines maintain their chemical and mechanical properties almost to their melting point. New research shows in detail how new phases in a nickel-based alloy form and evolve during heat treatment, providing clues to how these high-performance alloys could be improved.
Scientists at Ames Laboratory have demonstrated broadband terahertz (THz) wave generation using metamaterials. The discovery may help develop noninvasive imaging and sensing, and make possible THz-speed information communication, processing and storage.
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".
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.
Falls are a major problem for the elderly. Each year, one-third of adults over age 65 experience a fall, and one-third of those falls impact health and autonomy. The Swiss spin-off Gait Up just put an extremely thin motion sensor on the market which can detect the risk of a fall in an older person and is equally useful for sports and physical therapy.
Solid catalysts based on precious metals, such as palladium, are widely used in industry to promote a range of chemical reactions. Finding ways to minimize the consumption of expensive catalytic materials, however, remains a critical challenge. Researchers in Japan have now developed a nanostructured catalyst that makes extremely efficient use of trace amounts of catalytic palladium.
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 collaboration of researchers has discovered that sodium bismuthate can exist as a form of quantum matter called a 3-D topological Dirac semi-metal (3DTDS). This is the first experimental confirmation of 3-D Dirac fermions in the interior or bulk of a material, a novel state that was only recently proposed by theorists. It is a natural counterpart because of its magnetoresistive properties.
North Carolina State Univ. researchers have used silver nanowires to develop wearable, multi-functional sensors that could be used in biomedical, military or athletic applications, including new prosthetics, robotic systems and flexible touch panels. The sensors can measure strain, pressure, human touch and bioelectronic signals such as electrocardiograms.
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.
The atomic force microscope (AFM) uses a fine-tipped probe to scan surfaces at the atomic scale. But soon, thanks to efforts by scientists in The Netherlands, the AFM will soon be augmented with a new type chemical sensor, one that resembles a microscopic fountain pen. A hollow AFM cantilever acts as the pen, delivering droplets of mercury at the tip, which acts as a chemical sensor.
Researchers at the Univ. of Delaware have developed a “smart” hydrogel that can deliver medicine on demand, in response to mechanical force. Over the past few decades, smart hydrogels have been created that respond to pH, temperature, DNA, light and other stimuli.
Using an approach akin to assembling a club sandwich at the nanoscale, NIST researchers have succeeded in crafting a uniform, multi-walled carbon nanotube-based coating that greatly reduces the flammability of foam commonly used in upholstered furniture and other soft furnishings. The flammability of the nanotube-coated polyurethane foam was reduced 35% compared with untreated foam.
“The interface is the device,” Nobel laureate Herbert Kroemer famously observed, referring to the remarkable properties to be found at the junctures where layers of different materials meet. In today’s burgeoning world of nanotechnology, the interfaces between layers of metal oxides are becoming increasingly prominent. Realizing the vast potential of these metal oxide interfaces requires detailed knowledge of their electronic structure.
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.
Humans have for ages taken cues from nature to build their own devices, but duplicating the steps in the complicated electronic dance of photosynthesis remains one of the biggest challenges and opportunities for chemists. Currently, the most efficient methods we have for making fuel from sunlight and water involve rare and expensive metal catalysts. However, that is about to change.
Researchers have shown how to increase the efficiency of thin-film solar cells, a technology that could bring low-cost solar energy. The approach uses 3-D photonic crystals to absorb more sunlight than conventional thin-film cells. The synthetic crystals possess a structure called an inverse opal to make use of and enhance properties found in the gemstones to reflect, diffract and bend incoming sunlight.
Massachusetts Institute of Technology engineers have devised a way to measure the mass of particles with a resolution better than an attogram. Weighing these tiny particles, including both synthetic nanoparticles and biological components of cells, could help researchers better understand their composition and function.
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.
A new porous structure under development in German possesses essential properties of natural bone marrow and can be used for the reproduction of stem cells in the laboratory. The specific reproduction of these hematopoietic cells outside the body might facilitate new therapies for leukemia in a few years.