Science

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Needle beam could eliminate signal loss in on-chip optics: Harvard researchers create a light wave that propagates without spreading

An international, Harvard-led team of researchers have demonstrated a new type of light beam that propagates without spreading outwards, remaining very narrow and controlled along an unprecedented distance. This "needle beam," as the team calls it, could greatly reduce signal loss for on-chip optical systems and may eventually assist the development of a more powerful class of microprocessors.

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Top: A micrograph and diagram of the metallic gratings that produce the needle beam. Bottom: An approximation of the experimental setup. A laser is focused from the glass substrate side onto the device. Once the non-diffractive surface wave is created, detailed information on its intensity distribution is gathered using an ultrahigh-spatial-resolution near-field scanning optical microscope.

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Rust Never Sleeps: Berkeley Lab-led Observations of Electron Hopping in Iron Oxide Hold Consequences for Environment and Energy

Rust - iron oxide - is a poor conductor of electricity, which is why an electronic device with a rusted battery usually won't work. Despite this poor conductivity, an electron transferred to a particle of rust will use thermal energy to continually move or "hop" from one atom of iron to the next. Electron mobility in iron oxide can hold huge significance for a broad range of environment- and energy-related reactions, including reactions pertaining to uranium in groundwater and reactions pertaining to low-cost solar energy devices. Predicting the impact of electron-hopping on iron oxide reactions has been problematic in the past, but now, for the first time, a multi-institutional team of researchers, led by scientists at the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) have directly observed what happens to electrons after they have been transferred to an iron oxide particle.

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Iron oxide (rust) is a poor electrical conductor, but electrons in iron oxide can use thermal energy to hop from one iron atom to another. A Berkeley Lab experiment has now revealed exactly what happens to electrons after being transferred to an iron oxide particle.

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Proteins barge in to turn off unneeded genes and save energy

The sorcerer's apprentice started a water-carrying system, but couldn't stop it, and soon he was up to his neck in water, and trouble. Living cells have a better design: When they activate a gene, they have a system in reserve to turn it off. The cell does not want to waste energy making proteins it no longer needs. Cornell researchers have identified two mechanisms cells use and found they are designed to be quick.

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A few Angstroms make all the difference. The CueR protein binds to DNA at the start of a gene that protects against copper poisoning. When copper atoms bind to CueR, the protein changes shape just enough to twist the DNA - such a small distance that it can't be drawn in two dimensions - to turn on transcription of the gene. When the gene is no longer needed, the original form of CueR unceremoniously kicks the copper-bound form away, turning off transcription quickly to save energy.

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$18.5 million NSF grant to develop self-monitoring health devices

Penn State, North Carolina State University, the University of Virginia and Florida International University will collaborate on a national nanotechnology research effort to create self-powered devices to help people monitor their health and understand how the surrounding environment affects it.

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A schematic for an unobtrusive, wearable electronic health monitoring system. Penn State is part of a collaborative research effort to create self-powered devices to help people monitor their health.

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Dawn has Departed the Giant Asteroid Vesta

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This image is from the last sequence of images NASA's Dawn spacecraft obtained of the giant asteroid Vesta, looking down at Vesta's north pole as it was departing.

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New Method for Rapid Separation of Uranyl Ions from Aqueous Solutions

Iranian researchers from Birjand University managed to provide an efficient means for rapid and selective adsorption of uranyl ions from aqueous samples with the help of an external magnetic field.

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The mentioned research group has set its main goal on preparing selective and environmentally friendly adsorbents for fast separation and concentration of uranyl and thorium from aqueous solutions, for quite a while.

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Improvement of Photocatalytic Activity of Zinc Oxide

Iranian researchers from Islamic Azad University succeeded in improving crystalline growth and surface modification of ZnO layer in In2O3/SnO2/ZnO catalyst by using network accommodation between zinc and tin oxides and reducing the inductive tension in the heterojunction of the two oxides.

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The modification was used in order to increase the photocatalytic activity of the nanocatalyst. The catalysts synthesized through this method can be used cost-effectively at large scale in the purification of textile industry wastewater after more optimization.

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NASA's SDO Sees Massive Filament Erupt on Sun

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Swirls of green and red appear in an aurora over Whitehorse, Yukon on the night of September 3, 2012. The aurora was due to the interaction of a coronal mass ejection (CME) from the sun with Earth's magnetosphere. The CME left the sun on August 31 and arrived on September 3.

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Interfaces provide new control over oxides' electronic properties

Materials called transition metal oxides have physicists intrigued by their potentially useful properties -- from magnetoresistance (the reason a hard drive can write memory) to superconductivity.

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An artist's rendering of a transition metal oxide superlattice, with an actual transmission electron microscopy image superimposed on the left panel. The red is manganese, yellow is lanthanum and blue is strontium. The top is a Fermi surface map which illustrates how electrons move in the material.

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Performance Model of Biomolecules in Magnetic Fields Revealed by Scientists

Iranian researchers at Malek-e Ashtar University of Technology and Tarbiat Modarres University managed to discover a meaningful model for performance of biomolecules in magnetic fields by studying the effects of magnetic nanoparticles on the enzyme activity of Flavobacterium, modified with magnetic nanoparticles.

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Cell stabilization is the physical holding or connection of a cell in a particular place in a way that it can be used repeatedly and continuously.

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