EPA Funding Opportunity - Greater Research Opportunities Fellowships for Graduate Environmental Study

The U.S. Environmental Protection Agency, as part of its Greater Research Opportunities program, is offering Graduate Fellowships for master's and doctoral level students in the environmental fields of study. The deadline for receipt of pre-applications is October 18, 2005. Subject to availability of funding, the Agency plans to award approximately 15 new fellowships by July 21, 2006. Master's level students may receive support for a maximum of two years. Doctoral students may be supported for a maximum of three years, usable over a period of four years. The fellowship program provides up to $37,000 per year of support. Read more

DOT Funding Opportunity - Demonstration and Evaluation of Speed Management on Main Roads in Rural Communities

The Federal Highway Administration is contemplating the award of multiple demonstration and evaluation projects for a performance period of 24 months. The objective of these demonstration and evaluation projects is to determine the extent to which gateways lead to lower speeds and improved safety on main roads in rural communities. This cooperative agreement program requires each recipient to conduct a carefully planned demonstration and evaluation of implementing a gateway for speed management. Read more

Sandia Develops Secure Wireless Technology

Sandia National Laboratories News Release, 21 Jun 2005 Sandia National Laboratories in cooperation with Time Domain Corporation and KoolSpan Inc. has developed a secure wireless Ultra Wideband data communication network that can be used to help sensors monitor U.S. Air Force bases and DOE nuclear facilities and wirelessly control remotely operated weapon systems. Read more

Imaging Techniques: Particular Magnetic Insights

by Andreas Trabesinger Nature, 30 Jun 2005 A new imaging method intended for medical diagnosis, has been developed in the Philips research lab in Hamburg. The idea is that a liquid containing harmless magnetic particles is administered to the patient, who is then subjected to a magnetic field similar to that used in conventional magnetic resonance imaging. But in contrast to MRI, it is the particles themselves that are detected, rather than the response that they induce in surrounding tissues. Medical imaging is the main focus of the project, but magnetic particle imaging could also find applications in materials science, crack detection and fluid dynamics. Read more

High-Coupling-Efficiency Optical Interconnection Using a 90°-Bent Fiber Array Connector in Optical Printed Circuit Boards

by Mu Hee Cho et al. IEEE Photonics Technology Letters, March 2005 A high-coupling-efficiency optical interconnection has been demonstrated using a 90°-bent fiber array connector to deflect beams between surface-emitting lasers or surface-receiving photodiodes and optical layers embedded in a board. A 90°-bent fiber array is mounted in a tetragonal body with a millimeter scale size to make it suitable for passive packaging in the board. The bending radius of silica fibers in the connector was controlled to have 1.5mm resulting in bending loss of about 0.5 dB. An optical link of 2.5-Gb/s signals with a total interconnection loss of -1.3 dB was demonstrated using the connectors and a fiber-embedded board. Read more

Creating, Varying, and Growing Single-Site Molecular Contacts

by Mohamed Siaj & Peter H. McBreen Science, 22 Jul 2005 The known range of chemisorption bonds forms the toolbox for the design of electrical contacts in molecular electronics devices. Double-bond contacts to technologically relevant materials would be attractive for a number of reasons. They are truly single-site, bonding to a single surface atom. They obviate the need for a thiol linkage, and they may be amenable to further modification through olefin-metathesis methodologies. We report olefin-metathesis methods for establishing, varying, and growing thermally stable double-bond contacts to molybdenum carbide, a conducting material. Read more

Fermionic Bell-State Analyzer for Spin Qubits

by Hans-Andreas Engel & Daniel Loss Science, 22 Jul 2005 We propose a protocol and physical implementation for partial Bell-state measurements of Fermionic qubits, allowing for deterministic quantum computing in solid-state systems without the need for two-qubit gates. Our scheme consists of two spin qubits in a double quantum dot where the two dots have different Zeeman splittings and resonant tunneling between the dots is only allowed when the spins are antiparallel. This converts spin parity into charge information by means of a projective measurement and can be implemented with established technologies. This measurement-based qubit scheme greatly simplifies the experimental realization of scalable quantum computers in electronic nanostructures. Read more

Scrubbing Bubbles Hit the Streets

Associated Press Wired News, 22 Jul 2005 From catalytic converters to alternative fuels, the fight against big-city smog has for years been fought inside combustion engines and exhaust pipes. Now, scientists are taking the fight to the streets by developing "smart" building materials designed to clean the air with a little help from the elements. Using technology already available for self-cleaning windows and bathroom tiles, scientists hope to paint cities with materials that dissolve and wash away pollutants when exposed to sun and rain. Read more

Metal-Cooled Computing

by Simon Burns TechnologyReview.com, 22 Jun 2005 In many ways, Moore's Law -- the famous prediction by Gordon Moore, co-founder of chip manufacturer Intel, that microprocessor complexity will grow exponentially without an increase in price -- has held for four decades. But that complexity has come with a hidden "cost": heat. Packing more and more components and circuits onto a chip requires more electrical power to run it. And most of that power turns into heat, so that the latest chips can quickly exceed 100 degrees Centigrade, if not properly cooled. One potential solution to this growing problem is more commonly associated with nuclear reactors: liquid metal cooling. Read more

Japan Begins Quest for Fastest Supercomputer

Japan Times, 26 Jul 2005 The technology ministry aims to develop a next-generation supercomputer some 73 times faster than today's record-holder, ministry officials said Monday. According to the Education, Culture, Sports, Science and Technology Ministry, the planned supercomputer will operate at a maximum speed of 10 petaflops, or 10 quadrillion floating point operations per second. Read more

Could Cars That Read Minds Save Drivers From Themselves?

by William Diem New York Times, 18 Jul 2005 Pilots log hours in cockpit simulators before they ever take the controls of an airliner, practicing emergency procedures and learning the layout of a plane's instrument panel. Automakers also rely on simulators, though their intent is to study drivers, not train them. In the controlled laboratory setting of a driving simulator, researchers have discovered many things about drivers, including their reluctance to use all of a car's available braking power in a panic stop. Such findings have resulted in electronic systems that sense a panic situation -- by noting how sharply the driver first pushes the brake pedal -- and then continue to apply pressure even if the driver backs off. Read more

Creepy Crawlies to Explore Other Worlds

by Lewis Dartnell New Scientist, 23 Jul 2005 In Countless B-movies giant alien insectoids invade the Earth and wreak havoc, trampling through cities and tearing down buildings. Now we puny earthlings are hoping to turn the tables, and send insect-like robots to investigate the surface of Mars. These "biomimetic" robots that can walk, climb and fly like real creatures are already under development -- and some can almost think like them. Read more

Waveguide Growth: The Integrated View

by Joe McEntee fibers.org News, 25 Jul 2005 A UK research company called Plasma Quest has come up with a new take on sputtering technology that allows the deposition of thick layers of dielectric material onto silicon wafers at ambient temperature. The resulting structures exhibit excellent optical waveguiding properties and are said to be suitable for applications such as optical-chip interconnects, fibre-laser and fibre-detector coupling, as well as subsequent processing into photonic crystals. Read more

Massively Parallel Manipulation of Single Cells and Microparticles Using Optical Images

by Pei Yu Chiou, Aaron T. Ohta, & Ming C. Wu Nature, 21 Jul 2005 The ability to manipulate biological cells and micrometre-scale particles plays an important role in many biological and colloidal science applications. However, conventional manipulation techniques -- including optical tweezers, electrokinetic forces (electrophoresis, dielectrophoresis, travelling-wave dielectrophoresis), magnetic tweezers, acoustic traps and hydrodynamic flows -- cannot achieve high resolution and high throughput at the same time. Optical tweezers offer high resolution for trapping single particles, but have a limited manipulation area owing to tight focusing requirements; on the other hand, electrokinetic forces and other mechanisms provide high throughput, but lack the flexibility or the spatial resolution necessary for controlling individual cells. Here we present an optical image-driven dielectrophoresis technique that permits high-resolution patterning of electric fields on a photoconductive surface for manipulating single particles. It requires 100,000 times less optical intensity than optical tweezers. Using an incoherent light source (a light-emitting diode or a halogen lamp) and a digital micromirror spatial light modulator, we have demonstrated parallel manipulation of 15,000 particle traps on a 1.3 times 1.0 mm2 area. With direct optical imaging control, multiple manipulation functions are combined to achieve complex, multi-step manipulation protocols. Read more

Direct Observation of Electron Dynamics in the Attosecond Domain

by A. Föhlisch et al. Nature, 21 Jul 2005 Dynamical processes are commonly investigated using laser pump-probe experiments, with a pump pulse exciting the system of interest and a second probe pulse tracking its temporal evolution as a function of the delay between the pulses. Because the time resolution attainable in such experiments depends on the temporal definition of the laser pulses, pulse compression to 200 attoseconds (1 as = 10^-18 s) is a promising recent development. These ultrafast pulses have been fully characterized, and used to directly measure light waves and electronic relaxation in free atoms. But attosecond pulses can only be realized in the extreme ultraviolet and X-ray regime; in contrast, the optical laser pulses typically used for experiments on complex systems last several femtoseconds (1 fs = 10^-15 s). Here we monitor the dynamics of ultrafast electron transfer -- a process important in photo- and electrochemistry and used in solid-state solar cells, molecular electronics and single-electron devices -- on attosecond timescales using core-hole spectroscopy. We push the method, which uses the lifetime of a core electron hole as an internal reference clock for following dynamic processes into the attosecond regime by focusing on short-lived holes with initial and final states in the same electronic shell. This allows us to show that electron transfer from an adsorbed sulphur atom to a ruthenium surface proceeds in about 320 as. Read more

'Tall' Crystals from Tiny Templates

Ames Laboratory News Release, 21 Jul 2005 Achieving a first in the world of novel optical materials, researchers at the U. S. Department of Energy's Ames Laboratory are making 3-D photonic band gap crystals four millimeters square and 12 layers high without benefit of a "clean room" environment or the multimillion dollar equipment traditionally required to create such structures. The fundamental research, supported by the Basic Energy Sciences Office of the DOE's Office of Science, holds potential for significantly reducing the costs associated with fabricating PBG crystals, devices that make it possible to route, manipulate and modify the properties of light. Read more

To Make Stronger Platinum Jewelry, Add a Little Chromium

Johns Hopkins University News Release, 22 Jul 2005 Using a high-tech but low-cost technique, a Johns Hopkins undergraduate has tested tiny samples of four metal alloys to find the best blend for use in platinum jewelry. After evaluating four metal mixtures, student researcher Christopher Kovalchick determined that platinum combined with a small amount of chromium in a cold-rolled and heat treatment process displayed the greatest strength. Read more

Five New IEEE Periodicals to Debut in 2006

IEEE News Briefs, 24 Jun 2005 The IEEE will publish the following new periodicals next year:

• IEEE Computational Intelligence Magazine, sponsored by the IEEE Computational Intelligence Society
• IEEE Computer Architecture Letters, sponsored by the IEEE Computer Society
• IEEE Journal on Product Safety Engineering, sponsored by the IEEE Product Safety Engineering Society
• IEEE Transactions on Information Forensics and Security, sponsored by the IEEE Signal Processing Society
• IEEE Vehicular Technology Magazine, sponsored by the IEEE Vehicular Technology Society

Quantum Computers Go for a Spin

by Philip Ball news @ nature.com, 21 Jul 2005 Two physicists have come up with an idea that could crack the as yet unsolved problem of how to build a quantum computer, a device that would make a conventional supercomputer look like a Palm Pilot. Read more

Computer Vision System Detects Foreign Objects in Processed Poultry and Food Products

Georgia Institute of Technology Research News, 21 Jul 2005 Although metal detectors help commercial food processors keep metal fragments from ending up in finished products, these detectors can't identify plastic and other foreign objects. John Stewart, a research engineer at the Georgia Tech Research Institute, has been leading a development team in building a computer-vision system that identifies plastic and other unwanted elements in finished food products. Read more

Hope Revived for Storing Hydrogen in Nanocarbon

by Philip Ball Nature Materials Update, 21 Jul 2005 Could carbon nanostructures really be used to store hydrogen, for example in fuel-cell-powered electric vehicles? This enticing prospect was suggested eight years ago, when high storage densities were reported in carbon nanotubes. But researchers have struggled subsequently to reproduce those findings, and neither experiments nor theoretical calculations have convincingly shown that the target storage capacity specified by the US Department of Energy for practical applications can be reliably reached. Read more

Two-Dimensional Atomic Crystals

by K. S. Novoselov et al. Proceedings of the National Academy of Sciences, 26 Jul 2005 We report free-standing atomic crystals that are strictly 2D and can be viewed as individual atomic planes pulled out of bulk crystals or as unrolled single-wall nanotubes. By using micromechanical cleavage, we have prepared and studied a variety of 2D crystals including single layers of boron nitride, graphite, several dichalcogenides, and complex oxides. These atomically thin sheets (essentially gigantic 2D molecules unprotected from the immediate environment) are stable under ambient conditions, exhibit high crystal quality, and are continuous on a macroscopic scale. Read more

DoD Funding Opportunity - Reversible Barriers

The Reversible Barriers (ReBar) program is soliciting proposals due 14 September 2005. Military operations on the ground include both direct combat and other dangerous and labor-intensive activities such as searching buildings for weapons or personnel, hostage rescue, ground intelligence, surveillance, and reconnaissance, and more. These kinds of activities are especially prevalent in military operations in urban terrain and counter-insurgency, and are very manpower-intensive. The ability to quickly and easily prevent or restrict access to both building and outside areas would be tremendously advantageous to US forces, especially if this could be done in a rapidly reversible manner. The goal of the Reversible Barrier program is to develop barriers that can be rapidly emplaced and reversed to allow fluid US force movement. This new generation of barrier technology should have a set of features including (a) light-weight and portable, (b) very strong and resistant to various types of attack, (c) quick and easy to install, and (d) rapidly reversible only for U.S. and allied personnel. Read more

Power Electronics Drive Next-Generation Vehicles

by Ben Ames Military & Aerospace Electronics Web Exclusive, 20 Jul 2005 Engineers are building power integrated circuits and other power components to match growing current needs and the efficiencies of unmanned aerial vehicles, manned aircraft, spacecraft, and ocean-going ships, as well as armored combat vehicles. From electric-drive ships to hybrid Humvees, military vehicles that rely on electric motors rather than -internal-combustion engines will soon rely on advanced power electronics to handle huge voltages in their drive trains. Read more

Nominate an IEEE Senior Member

Every year, IEEE elevates many of its members to the level of IEEE Senior Member, the highest grade of membership for which an individual may apply. Potential senior members must have ten years of experience in an IEEE field, five years of "significant performance," and written references from three IEEE Senior Members or Fellows. IEEE Society members can earn rewards for their societies when they nominate IEEE members for elevation. Completed Senior Member applications and reference forms must be submitted by 5 November. Read more

Two IEEE Societies Call for Nominations

The IEEE Electron Devices Society (EDS) is looking for candidates for election to its Administrative Committee (AdCom), the society's governing body. The IEEE-EDS AdCom has 22 members and meets twice annually. There are eight seats open for this year's election. The deadline for submission of nominations is 15 October 2005. Read more The IEEE Circuits and Systems Society is looking for willing and knowledgeable members to serve as Society officers. Society officers are elected by the Board of Governors, yet any eligible Society member can apply. Positions will be filled starting January 2006 and the nomination deadline is 1 September 2005. All members with engineering expertise and societal spirit are encouraged to run. Read more

Proceedings of the IEEE Focuses on Flexible Electronics

A two-part examination of flexible electronics technology appears in Proceedings of the IEEE, the flagship journal of the IEEE. The July issue focuses on systems and applications, while the August issue will examine materials and devices. The term flexible macroelectronics represents a range of device and materials technologies built on flexible and conformal substrates such as thin plastic or metal foils. Papers in these issues place a special emphasis on ideas and concepts that will enable commercial applications of flexible and large area electronics. Read more

Spin Control

by Harold Miller, Steven Massey, & Alan Paxton oemagazine, June/July 2005 Leaders in the defense community continue to be interested in understanding the potential of high-power lasers for military applications. The promise of light-speed, precision engagement of soft targets, along with the multitude of other possible applications enabled by alternate wavelengths, powers, and beam formats compels technologists to consider laser-based systems in their planning. Although chemical lasers have been shown to be capable of very high output powers, compact, electrically driven solid-state lasers appear to be the enabling technology for many of the envisioned scenarios. Read more

A New Eye on Law Enforcement

by Benjamin ver Steeg & Trent Ridder oemagazine, June/July 2005 Although alcohol testing is typically associated with drunk driving, it also plays significant roles in probation monitoring, workplace safety, and emergency medicine. Current measurement techniques suffer from two key limitations: they require the handling of a bodily fluid, which gives rise to biohazard concerns, and they require some degree of direct subject supervision from a test administrator. A recent advance in optical testing methods promises to overcome these limitations by simultaneously offering improved subject safety and the ability to conduct completely unsupervised testing. Our team has developed a touch-based alcohol monitoring technology that uses near-infrared reflectance spectroscopy to noninvasively measure alcohol through a subject's skin. This creates a rapid, easy-to-use method for determining alcohol concentration in a variety of environments. Read more

Getting the Most from Multiprocessor SoC Design

by Ashish Dixit EE Times, 20 Jul 2005 For many applications, allocating performance among all of the tasks in a system-on-chip design is much easier and provides greater design flexibility with multiple CPUs than with just one control processor and multiple blocks of logic. Just using bigger control processors will not satisfy the widely varying computational demands of many of today’s designs because bigger processors often require too much power, especially for consumer devices. Read more

Mind May Affect Machines

by Kim Zetter Wired News, 19 Jul 2005 For 26 years, strange conversations have been taking place in a basement lab at Princeton University. No one can hear them, but they can see their apparent effect: balls that go in certain directions on command, water fountains that seem to rise higher with a wish and drums that quicken their beat. Yet no one hears the conversations because they occur between the minds of experimenters and the machines they will to action. Read more

Gold in Garbage: Industries Transform Trash to Energy

by Emery P. Dalesio USATODAY, 13 Jul 2005 Jim Voss hopes his company will make a fortune out of garbage -- specifically the methane gas produced when tons of trash decay in landfills across the nation. Read more

Machine in Motion

by Gregory T. Huang Technology Review, August 2005 They don’t make robots like they used to. Instead of plodding through a limited repertory of programmed moves, Toddler learns to walk with a loose, easy gait. Built by Russ Tedrake of MIT’s Computer Science and Artificial Intelligence Laboratory, the robot combines ideas from bio-mechanics, control theory, and machine learning to push the limits of today’s robotic technology. Read more

One-Dimensional Hole Gas in Germanium/Silicon Nanowire Heterostructures

by Wei Lu et al. Proceedings of the National Academy of Sciences, 19 Jul 2005 Two-dimensional electron and hole gas systems, enabled through band structure design and epitaxial growth on planar substrates, have served as key platforms for fundamental condensed matter research and high-performance devices. The analogous development of one-dimensional (1D) electron or hole gas systems through controlled growth on 1D nanostructure substrates, which could open up opportunities beyond existing carbon nanotube and nanowire systems, has not been realized. Here, we report the synthesis and transport studies of a 1D hole gas system based on a free-standing germanium/silicon (Ge/Si) core/shell nanowire heterostructure. Room temperature electrical transport measurements clearly show hole accumulation in undoped Ge/Si nanowire heterostructures, in contrast to control experiments on single-component nanowires. Low-temperature studies show well-controlled Coulomb blockade oscillations when the Si shell serves as a tunnel barrier to the hole gas in the Ge channel. Transparent contacts to the hole gas also have been reproducibly achieved by thermal annealing. In such devices, we observe conductance quantization at low temperatures, corresponding to ballistic transport through 1D subbands, where the measured subband energy spacings agree with calculations for a cylindrical confinement potential. In addition, we observe a "0.7 structure," which has been attributed to spontaneous spin polarization, suggesting the universality of this phenomenon in interacting 1D systems. Lastly, the conductance exhibits little temperature dependence, consistent with our calculation of reduced backscattering in this 1D system, and suggests that transport is ballistic even at room temperature. Read more

Graphene Nanostructures as Tunable Storage Media for Molecular Hydrogen

by Serguei Patchkovskii et al. Proceedings of the National Academy of Sciences, 14 Jul 2005 Many methods have been proposed for efficient storage of molecular hydrogen for fuel cell applications. However, despite intense research efforts, the twin U.S. Department of Energy goals of 6.5% mass ratio and 62 kg/m³ volume density has not been achieved either experimentally or via theoretical simulations on reversible model systems. Carbon-based materials, such as carbon nanotubes, have always been regarded as the most attractive physisorption substrates for the storage of hydrogen. Theoretical studies on various model graphitic systems, however, failed to reach the elusive goal. Here, we show that insufficiently accurate carbon-H2 interaction potentials, together with the neglect and incomplete treatment of the quantum effects in previous theoretical investigations, led to misleading conclusions for the absorption capacity. A proper account of the contribution of quantum effects to the free energy and the equilibrium constant for hydrogen adsorption suggest that the DoE specification can be approached in a graphite-based physisorption system. The theoretical prediction can be realized by optimizing the structures of nano-graphite platelets, which are light-weight, cheap, chemically inert, and environmentally benign. Read more

'Smart' Device to Help Elderly People Avoid Falls

United Press International PhysOrg, 20 Jul 2005 A group of Stanford University students is developing a vibrating ankle brace designed to assist elderly people in avoiding falls. The "smart" brace is fitted with a tiny chip that continuously monitors the position of the wearer's ankle, CNN said. If the chip detects a roll greater than normal, it vibrates, thereby sending a signal to the wearer's brain that they must change the position of their foot or shift their balance in order to avoid a fall. The students -- Tim Ramsey, Ryan McDonnell, Buzzy Bonneau, Tejas Mazmudar, Jeremy Dittmer and Surag Mantri -- told CNN they wanted to develop something that would detect a body's position in relation to its surroundings -- a sense that decreases as people age. They wanted their device to be more discreet than current devices used to prevent falls, such as walkers and canes. The students are participating in the California school's Biodesign Innovation Program. Officials said the design is in its preliminary stages.

Patent Highlights, 14 Jul 2005

optics.org News, 14 Jul 2005 The pick of this week's patents including a lens array from mobile phone giant Nokia. • Brightness preserving laser beam shaper • Optical device • Imaging device Read more

All Traffic, All the Time and Just a Click Away

by Joe Sharkey New York Times, 19 Jul 2005 Wave goodbye to good old Cap'n Bob clattering up there in the clouds in NewsChopper 99, squinting through binoculars and trying to keep track of a world of traffic. Though traffic helicopters are still on the job, an era may well be ending. Because of technological advances in the way traffic can be measured and monitored from roadside digital sensors, there is less and less need for a chopper in the air. Read more

I, Roommate: The Robot Housekeeper Arrives

by Mark Allen New York Times, 14 Jul 2005 When my home robot arrived last month, its smiling inventors removed it from its box and laid it on its back on my living room floor. They leaned over and spoke to it, as one might to a sleeping child. It straightened, let out a little beep, lighted up, looked left and right, and then, amazingly, stood and faced me. Read more

Finger Scanner Fine-Tunes Car Safety Settings

by Will Knight NewScientist.com, 14 Jun 2005 A dashboard finger scanner could prevent thousands of car injuries each year by fine-tuning crash restraint systems to a passenger's bone density. Read more

Cool It

by Daniel Pendick New Scientist, 16 Jul 2005 Jonathan is outside, roving the yard at his parents' 6-acre farm in south-east Illinois in an electric golf cart. Small-boned and a little on the short side, Jonathan could be mistaken for a skinny high-school kid. In fact he is 30 years old. Jonathan has learning disabilities which doctors believe are the result of a stroke he suffered at birth. But the biggest limitation on his life is epilepsy. Steven Rothman thinks he may have found a way to liberate people like Jonathan. Rothman's idea is to implant a small chip in the skull that detects the start of a seizure and quickly cools the misfiring cells. If it works, the brain-chilling chip will completely douse an electrical storm before it develops, and the patient won't even know it. Read more

Animal and Robot Mixed Societies

by G. Caprari et al. IEEE Robotics & Automation Magazine, June 2005 A group of cockroaches have found a friend in a matchbox-sized robot called Insbot. Developed at the Swiss Federal Institute of Technology in Lausanne, Insbot has learned how to mimic cockroaches' behaviour and interact with a colony of the insects. The device was developed to show how artificial systems could interact with animals in future mixed societies. Read more

Wearable Camera Can Restore Lost Memories

by Paul Marks New Scientist, 2 Jul 2005 A wearable camera that automatically snaps thousands of photos of the people you meet, the places you go, the things you do and even the food you eat is proving to be a powerful aid for people with impaired memory. Read more

Take It To the Limit

by Dana Mackenzie. New Scientist, 9 Jul 2005 Noise is the blight of the information age. It can be far more than an annoyance: if you send instructions to an interplanetary spacecraft, and the message gets scrambled going through the ionosphere, your probe might fire its engines at the wrong time. But now noise has met its match, in the form of two miraculous methods for pulling clear messages out of what was previously considered to be undecipherable static. It's like hearing a whisper in a thunderstorm or reading road signs in a blizzard. Read more

Enhancement of Room-Temperature Plasticity in a Bulk Metallic Glass by Finely Dispersed Porosity

by Takeshi Wada & Akihisa Inoue Applied Physics Letters, 20 Jun 2005 Melts of Pd_42.5Cu₃₀Ni_7.5P₂₀ (at. %) held under pressurized hydrogen are cast into bulk metallic glass (BMG) rods with fine (20–30 µm diameter) pores uniformly dispersed. The low overall porosities (<4%)>–3, compared to 16 MJ m^–3 for the pore-free BMG. The pores force the proliferation of shear bands below the overall failure stress, a process of interest for toughening BMGs, materials for which shear localization in deformation restricts structural applications. Read more

Nanotubes Put in Their Place

by Philip Ball Nature Materials Update, 10 Jul 2005 If carbon nanotubes are ever going to be useful as components of nanoscale electronic circuits or sensors, it will be necessary to be able to position them accurately on a surface such as a silicon chip, with control over the nanotube size and molecular structure. This has so far posed a difficult challenge, but a team of researchers at Columbia University in New York has now found a way to achieve it. Read more

Highly Controlled Acetylene Accommodation in a Metal−Organic Microporous Material

by Ryotaro Matsuda et al. Nature, 14 Jul 2005 Metal-organic microporous materials (MOMs) have attracted wide scientific attention owing to their unusual structure and properties, as well as commercial interest due to their potential applications in storage, separation and heterogeneous catalysis. One of the advantages of MOMs compared to other microporous materials, such as activated carbons, is their ability to exhibit a variety of pore surface properties such as hydrophilicity and chirality, as a result of the controlled incorporation of organic functional groups into the pore walls. This capability means that the pore surfaces of MOMs could be designed to adsorb specific molecules; but few design strategies for the adsorption of small molecules have been established so far. Here we report high levels of selective sorption of acetylene molecules as compared to a very similar molecule, carbon dioxide, onto the functionalized surface of a MOM. The acetylene molecules are held at a periodic distance from one another by hydrogen bonding between two non-coordinated oxygen atoms in the nanoscale pore wall of the MOM and the two hydrogen atoms of the acetylene molecule. This permits the stable storage of acetylene at a density 200 times the safe compression limit of free acetylene at room temperature. Read more

AWG Advances Foster Optimism, Momentum

by G. Ferris Lipscomb fibers.org News, 4 Jul 2005 New developments in arrayed-waveguide-grating (AWG) technology have allowed AWGs to regain dominance in high-channel-count applications and earn significant share at low channel counts. AWGs provide optical mux/demux in DWDM systems, efficiently placing 40 or even 80 different DWDM wavelengths onto an optical fibre and extracting those wavelengths at the other end of the transmission. Read more

Interworking Advances in the Enterprise WAN

by Dave Parks fibers.org News, 11 Jul 2005 These days, Ethernet is an increasingly sought-after alternative for high-bandwidth enterprise WAN requirements. On the back of that demand, Ethernet service interworking is emerging as a mainstream opportunity for both network equipment vendors and service providers. Read more

Decoy State Quantum Key Distribution

by Hoi-Kwong Lo, Xiongfeng Ma, & Kai Chen Physical Review Letters, 16 Jun 2005 There has been much interest in quantum key distribution. Experimentally, quantum key distribution over 150 km of commercial Telecom fibers has been successfully performed. The crucial issue in quantum key distribution is its security. Unfortunately, all recent experiments are, in principle, insecure due to real-life imperfections. Here, we propose a method that can for the first time make most of those experiments secure by using essentially the same hardware. Our method is to use decoy states to detect eavesdropping attacks. As a consequence, we have the best of both worlds -- enjoying unconditional security guaranteed by the fundamental laws of physics and yet dramatically surpassing even some of the best experimental performances reported in the literature. Read more

Use of Patterned Laser Liftoff Process and Electroplating Nickel Layer for the Fabrication of Vertical-Structured GaN-Based Light-Emitting Diodes

by Shui-Jinn Wang et al. Applied Physics Letters, 4 Jul 2005 The fabrication process and performance characteristics of a vertical-structured GaN-based light-emitting diode (VM-LED) employing nickel electroplating and patterned laser liftoff techniques are presented. As compared to regular LED, the forward voltage drop of the VM-LED at 20–80 mA is about 10%–21% lower, while the light output power (L_op) is more than twice in magnitude. Especially, the L_op exhibits no saturation or degradation at an injection current up to 520 mA which is about 4.3 times higher than that of the regular one. Substantial improvements in the VM-LEDs performances are mainly attributed to the use of metallic substrate which results in less current crowding, larger effective area, and higher thermal conductivity. Read more

Base on Skis Wins Polar Contract

BBC News, 18 July, 2005 The British Antarctic Survey's new base will be produced by an engineering and architecture consortium in the UK. The concept by Faber Maunsell and Hugh Broughton Architects for the Halley VI station will be built on the floating Brunt Ice Shelf in the Antarctic. The base will host scientists all year round in temperatures ranging from -5C to -40C and will be raised on skis so it can be moved. Read more

Voice-to-Voice Translation Machine Perfects Bedside Manner

University of Southern California News Release, 29 Jun 2005 Three years of work by a large interdisciplinary team at the University of Southern California has created a rudimentary but working two-way voice translation system that allows an English-speaking doctor to talk to a Persian-speaking patient. Read more

Smart Coatings' Research Shows The Virtues of Superficiality

by John Bohannon Science, 15 Jul 2005 Clothing with computers woven into the fabric. Microscopic robots that make repairs with tools the size of a virus. No question about it: Nanotechnology, the applied science of the very small, has generated its share of megahype. For companies researching nanomaterials, however, profitability is the priority -- and not in the dreamy future but now. Many are concluding that the beauty of the technology is literally skin deep. Read more

To Physicists' Surprise, a Light Touch Sets Tiny Objects Aquiver

by Adrian Cho Science, 15 Jul 2005 Physicists have set a tiny disk of glass vibrating by "whistling" light through it. The effect could lead to optically controlled micromachines but might also limit the sensitivity of giant gravitational-wave detectors. Read more

The Renaissance of Magnetoelectric Multiferroics

by Nicola A. Spaldin & Manfred Fiebig Science, 15 Jul 2005 Magnetoelectric multiferroics combine ferromagnetism (a spontaneous magnetization that can be switched by a magnetic field) and ferroelectricity (a spontaneous electric polarization that can be switched by an electric field) in the same phase. They have tremendous potential for applications, not only because they possess the properties of both parent phenomena, but also because coupling between ferromagnetism and ferroelectricity can lead to additional novel effects. Spaldin and Fiebig discuss the factors behind the recent resurgence of interest in magnetoelectric multiferroics, describe some exciting results emerging from the current research activities, and point to important challenges and directions for future work. Read more

Where Do the Dopants Go?

by Scott Roy & Asen Asenov Science, 15 Jul 2005 As the field-effect transistors used in modern electronic devices continue to shrink, scientists and engineers face new challenges. Roy and Asenov discuss one such challenge: the problem that as device sizes shrink beyond a certain size, atomic-scale differences between devices result in different macroscopic properties. In particular, the locations and numbers of dopant atoms, introduced to alter the electrical properties of regions of the transistor, differ from device to device. The authors discuss recent successes in modeling the dopant distributions and their effects on transistor properties. Such simulations may help researchers to design devices that are resistant to fluctuations in dopant distributions. Read more

Structural Relaxation of Polymer Glasses at Surfaces, Interfaces, and In Between

by Rodney D. Priestley et al. Science, 15 Jul 2005 We analyzed the glassy-state structural relaxation of polymers near surfaces and interfaces by monitoring fluorescence in multilayer films. Relative to that of bulk, the rate of structural relaxation of poly(methyl methacrylate) is reduced by a factor of 2 at a free surface and by a factor of 15 at a silica substrate interface; the latter exhibits a nearly complete arresting of relaxation. The distribution in relaxation rates extends more than 100 nanometers into the film interior, a distance greater than that over which surfaces and interfaces affect the glass transition temperature. Read more

NSF Program Solicitation - Materials World Network: Cooperative Activity in Materials Research between U.S Investigators and Their Counterparts Abroad

Program Solicitation NSF 05-594 Continued progress in materials research is increasingly dependent upon collaborative efforts among several different disciplines, as well as closer coordination among funding agencies and effective partnerships involving universities, industry, and national laboratories. In addition, because of the growing interdependence of the world's economies, partnerships are important not only at the national level but from an international point of view as well. The National Science Foundation is working jointly with counterpart national, regional and multinational funding organizations worldwide to enhance opportunities for collaborative activities in materials research between US investigators and their colleagues abroad. This solicitation describes an activity to foster opportunities for such collaborations. It includes joint activities between NSF and funding organizations in Europe, Africa, Asia and other regions. Read more

The Greening of GE

by Peter Fairley IEEE Spectrun Online, accessed 13 Jul 2005 So far, the relationships between big energy companies and alternative energy technologies have been a lot like the marriages that unite Hollywood stars. Begun amid lofty promise and swooning media attention, all too often they soon descend into dysfunction and divorce. Now, into this boulevard of broken marriages comes General Electric Co., a pioneer of the fossil-fired and nuclear technologies that powered the 20th century -- but also, thanks to a legacy of pollution stemming from its use of polychlorinated biphenyls, a symbol of corporate denial. After largely ignoring alternative energy for most of its existence, GE has jumped in headfirst. Read more

Engineers of Tomorrow Need Broader Training Today

The National Academies News Release, 23 Jun 2005 Today's engineering students may not be adequately educated to meet the demands that will be made of their profession in 2020, says a new report from the National Academies' National Academy of Engineering. The undergraduate engineering experience needs to be reshaped to attract students to the profession, prepare them to compete in the global marketplace, and ensure that America's pre-eminence in engineering is not lost, said the committee that wrote the report. Read more

UAVs Poised To Take the Next Step into Combat

by J.R. Wilson Military & Aerospace Electronics, June 2005 Unmanned Aerial Vehicles (UAVs) first saw combat in the first Persian Gulf War of 1991, where Iraqi soldiers surrendered to a Pioneer UAV rather than have it direct ship-launched cruise missiles on their location. UAVs entered a new era in the second Persian Gulf War of 2003, as more advanced Predator UAVs, armed with Hellfire missiles, became the first robots to engage in combat as aggressors. The future of continued U.S. air superiority will involve an increasingly large contingent of armed UAVs and a new generation of Air Force and Navy unmanned combat aerial vehicles (UCAVs), flying missions that manned attack aircraft previously flew, often in joint missions under the control of fighter-bomber pilots. Read more

Weather Forecasters Turn to High Technology

by Ben Ames Military & Aerospace Electronics, June 2005 From warfighting to civilian airline schedules, weather controls our lives. A sandstorm in the desert or wind shear above an aircraft carrier can bring entire battle plans to a halt. So the modern meteorologist builds forecasting models on powerful computers, and pulls data from radars, satellites, and a global network of sensors deployed on airplanes, weather balloons, and ocean buoys. Read more

Researcher Calls for 'Software-Centric' SoC Design

by Richard Goering EE Times, 12 Jul 2005 The problem with system-on-chip design is that software and hardware designers live in separate worlds, according to Hiroaki Takada, professor of information at Nagoya University in Japan and developer of a "software-centric" system-level design system. "I think the difficulty in communication between hardware and software engineers is a serious obstacle for deciding appropriate hardware/software partitioning," Takada said. Read more

Start-Up Zeros In on Hydrogen Fuel Cells

by Michael Kanellos ZDNet News, 11 Jul 2005 Michael Lefenfeld and James Dye of Signa Chemistry wanted to make rooms smell better. Instead, they stumbled on a way that could make hydrogen fuel cells a practical reality. Read more

Microsoft Presses Pedal on In-Car Software

by Ina Fried ZDNet News, 12 Jul 2005 Microsoft on Tuesday cranked up its long-running effort to get its software inside cars, announcing a new version of its Windows Automotive software. Read more

Beam It Right There, Scotty

Associated Press Wired News, 10 Jul 2005 For years, the U.S. military has explored a new kind of firepower that is instantaneous, precise and almost inexhaustible: beams of electromagnetic energy. "Directed-energy" pulses can be throttled up or down depending on the situation, much like the phasers on Star Trek could be set to kill or merely stun. Such weapons are now nearing fruition. But logistical issues have delayed their battlefield debut -- even as soldiers in Iraq encounter tense urban situations in which the nonlethal capabilities of directed energy could be put to the test. Read more

Making a Plug for Hybrids

by Matthew Shechmeister Wired News, 11 Jul 2005 As founder of CalCars, a nonprofit group that promotes fuel-efficient autos, Kramer has high hopes for a project aimed at convincing automakers to manufacture plug-in versions of their hybrid cars. As part of the project, the group recently unveiled a modified Toyota Prius that can be charged from a household power outlet. Read more

MIT Starts Second Wireless Revolution

PhysOrg, 12 Jul 2005 Wireless companies are investing big in new infrastructure that can handle the ever-increasing demand for inexpensive delivery of voice and data. But the solid-state amplifiers that the nation's roughly 200,000 wireless base stations now use to communicate with cell phones and other electronic devices are costly, generate excessive heat (requiring bulky cooling equipment) and need large backup batteries. MIT researchers are developing an alternative: the first radio frequency (RF) power amplifier based on a ribbon-beam vacuum electron device. The new amplifier combines a half-century-old technology-vacuum electron devices, or "vacuum tubes" in the old terminology-with a recent MIT breakthrough: an elliptical, or "ribbon," electron beam. Read more

Chaos in Computer Performance

by Hugues Berry, Daniel Gracia Pérez, & Olivier Temam arXiv.org e-Print archive, 13 Jun 2005 Modern computer microprocessors are composed of hundreds of millions of transistors that interact through intricate protocols. Their performance during program execution may be highly variable and present aperiodic oscillations. In this paper, we apply current nonlinear time series analysis techniques to the performances of modern microprocessors during the execution of prototypical programs. While variability clearly stems from stochastic variations for several of them, we present pieces of evidence strongly supporting that performance dynamics during the execution of several other programs display low-dimensional deterministic chaos, with sensibility to initial conditions comparable to textbook models. Taken together, these results confirm that program executions on modern microprocessor architectures can be considered as complex systems and would benefit from analysis with modern tools of nonlinear and complexity science. Read more

Doping the Undopable

by Giulia Galli1 Nature, 7 Jul 2005 Impurities that increase the number of electron carriers are essential in most bulk semiconductors. Introducing such foreign atoms into semiconductor nanocrystals is fiddly, and requires exact knowledge of the material's surface. Read more

Computer Hardware: Silicon Down to the Wire

by Colin Macilwain Nature, 7 Jul 2005 Microchip-makers are starting to look beyond silicon, and what they see is a semiconductor industry of a very different complexion -- but not for some time yet. Read more

Self-Assembled Nanobridge Formation and Spontaneous Growth of Metal-Induced Nanowires

by Joondong Kim et al. Applied Physics Letters, 20 Jun 2005 Self-assembled nanobridges, 30–80 nm in diameter and 1–2 µm in length, have been fabricated using spontaneously grown nanowires by the metal-induced growth method at 575 °C. Ni as a catalyst was first deposited on SiO2-coated Si wafers. Si was sputtered from a Si target in a dc magnetron system. A solid-state reaction of Si with Ni provided highly linear nanowires. These nanowires have a single-crystal NiSi composition. Laterally propagated nanowires formed nanobridges passing through a vertically trenched region, without nanowires on the trench sidewall. The nanobridge formation is repeatably governed by the Ni deposition. The self-assembled nanobridge can be applied to form nanocontacts at relatively low temperatures. Read more

New Roles for Robots

by John Teresko IndustryWeek, 1 Jul 2005 Once viewed largely as a way to save on labor costs, robots today have taken on more significant roles in manufacturing. They're part of global competitiveness plans and are seeing, moving and servicing better than ever. Read more

The Debate's Over: Globe Is Warming

by Dan Vergano USA TODAY, 12 Jun 2005 Don't look now, but the ground has shifted on global warming. After decades of debate over whether the planet is heating and, if so, whose fault it is, divergent groups are joining hands with little fanfare to deal with a problem they say people can no longer avoid. Read more

Synthesis and Characterization of Water Soluble Single-Walled Carbon Nanotube Graft Copolymers

by Bin Zhao et al. Journal of the American Chemical Society, 12 May 2005 Poly(aminobenzene sulfonic acid) (PABS) and polyethylene glycol (PEG) were covalently attached to single-walled carbon nanotubes (SWNTs) to form water-soluble graft copolymers. Quantitative near-IR (NIR) spectroscopic studies of these SWNT graft copolymers indicate a water solubility of about 5 mg/mL, and atomic force microscopy studies show a fairly uniform length and diameter. On the basis of thermogravimetric analysis, the loading of SWNTs in the graft copolymers is estimated to be 30% for SWNT-PABS and 71% for SWNT-PEG. NIR spectroscopic studies of SWNT-PABS show that this graft copolymer has a ground state that is a hybrid of the electronic structures of the isolated PABS and SWNT macromolecules. Read more

Doping Semiconductor Nanocrystals

by Steven C. Erwin et al. Nature, 7 Jul 2005 Doping -- the intentional introduction of impurities into a material -- is fundamental to controlling the properties of bulk semiconductors. This has stimulated similar efforts to dope semiconductor nanocrystals. Despite some successes, many of these efforts have failed, for reasons that remain unclear. For example, Mn can be incorporated into nanocrystals of CdS and ZnSe, but not into CdSe -- despite comparable bulk solubilities of near 50 per cent. These difficulties, which have hindered development of new nanocrystalline materials, are often attributed to 'self-purification', an allegedly intrinsic mechanism whereby impurities are expelled. Here we show instead that the underlying mechanism that controls doping is the initial adsorption of impurities on the nanocrystal surface during growth. We find that adsorption -- and therefore doping efficiency -- is determined by three main factors: surface morphology, nanocrystal shape, and surfactants in the growth solution. Calculated Mn adsorption energies and equilibrium shapes for several nanocrystals lead to specific doping predictions. These are confirmed by measuring how the Mn concentration in ZnSe varies with nanocrystal size and shape. Finally, we use our predictions to incorporate Mn into previously undopable CdSe nanocrystals. This success establishes that earlier difficulties with doping are not intrinsic, and suggests that a variety of doped nanocrystals -- for applications from solar cells to spintronics -- can be anticipated. Read more

An Intrinsic Limit to Quantum Coherence due to Spontaneous Symmetry Breaking

by Jasper van Wezel, Jeroen van den Brink, & Jan Zaanen Physical Review Letters, 17 Jun 2005 We investigate the influence of spontaneous symmetry breaking on the decoherence of a many-particle quantum system. This decoherence process is analyzed in an exactly solvable model system that is known to be representative of symmetry broken macroscopic systems in equilibrium. It is shown that spontaneous symmetry breaking imposes a fundamental limit to the time that a system can stay quantum coherent. This universal time scale is t_spon2N/(k_BT), given in terms of the number of microscopic degrees of freedom N, temperature T, and the constants of Planck () and Boltzmann (k_B). Read more

Holographic Assembly of Quasicrystalline Photonic Heterostructures

by Yael Roichman & David G. Grier Optics Express, 11 Jul 2005 Quasicrystals have a higher degree of rotational and point-reflection symmetry than conventional crystals. As a result, quasicrystalline heterostructures fabricated from dielectric materials with micrometer-scale features exhibit interesting and useful optical properties including large photonic bandgaps in two-dimensional systems. We demonstrate the holographic assembly of two-dimensional and three-dimensional dielectric quasicrystalline heterostructures, including structures with specifically engineered defects. The highly uniform quasiperiodic arrays of optical traps used in this process also provide model aperiodic potential energy landscapes for fundamental studies of transport and phase transitions in soft condensed matter systems. Read more

Sensitivity of Ammonia Interaction with Single-Walled Carbon Nanotube Bundles to the Presence of Defect Sites and Functionalities

by Xue Feng et al. Journal of the American Chemical Society, 8 Jul 2005 (web release) Ammonia adsorption on single-walled carbon nanotubes (SWNTs) was studied by means of infrared spectroscopy at both cryogenic (~94 K) and room (~300 K) temperatures. At 94 K, vacuum-annealed SWNTs showed no detectable ammonia uptake. However, the ammonia adsorption was found to be sensitive to the functionalities and defects on the nanotube surfaces. NH3 adsorption was detected on HNO3-treated nanotubes, characterized by significant functionalities and defects, prior to vacuum annealing. NH3 desorbed from those nanotubes above 140 K, indicating a weak adsorbate-nanotube interaction (~30 kJ/mol). Exposure of annealed samples to ambient air, which possibly regenerated functionalities and defects on nanotube surfaces, restored partially the ammonia uptake capacity. No ammonia adsorption on SWNTs was observed by infrared spectroscopy at room temperature with up to 80 Torr dosing pressure. This work suggests the influence of functionalities and/or defect densities on the sensitivity of SWNT chemical gas sensors. Our theoretical studies on NH3 adsorption on pristine and defective tubes, as well as oxidized tubes, corroborate these findings. Read more

The PediPump: A New Ventricular Assist Device for Children

by Brian W. Duncan et al. Artificial Organs, July 2005 Abstract: Options for mechanical circulatory support for the treatment of end-stage heart failure in children are limited. Ventricular assist devices (VADs), which have revolutionized cardiac care in adults, remain largely unavailable for pediatric applications. The PediPump is a new rotary dynamic VAD designed to provide support for the entire range of patient sizes encountered in pediatrics. Despite being much smaller than currently available VADs, which makes it suitable for even newborn circulatory support, the PediPump demonstrates excellent hemodynamic performance. Read more

Broadband Over Powerline Gains Investors and Detractors

by John Walko EE Times, 12 Jul 2005 A leading market researcher has warned that broadband over powerline may not make it in an increasingly competitive DSL and cable market, just as heavyweight corporations, Google, Goldman Sachs and Hearst have invested in a major utility providing fast data access over AC power lines, and IBM is reported to be partnering with another utility to trial the technology. Read more

Silly Putty Probe at Sandia

Sandia National Laboratories News Release, 8 Jul 2005

Squaring off with Silly Putty -- a material scientist's worstnightmare -- a Sandia National Laboratories researcher hasdemonstrated that a unique microscope quick enough to measure changesin this "liquid solid" may be the most effective tool for measuringless extreme plastic behavior in the structures of more widely usedmaterials. Read more

Teaching Qubits New Tricks

by Charles Seife Science, 8 Jul 2005 Quantum computers will shatter the encryption that makes Internet commerce safe, search databases at unthinkable speeds, and crank out ciphers that nature itself guarantees secure -- if they can be built. For years, scientists thought that would never happen because the same laws of physics that make quantum computers so powerful seemed to make a practical prototype impossible. But in 1995, when they discovered a means of preserving fragile quantum information despite those laws, quantum computing took a step closer to reality. The heart of the discovery was a way to correct errors in quantum information without destroying the information itself. These so-called quantum error correcting codes lie at the heart of quantum-computer research. Read more

Skeleton of Euplectella sp.: Structural Hierarchy from the Nanoscale to the Macroscale

by Joanna Aizenberg et al. Science, 8 Jul 2005 Structural materials in nature exhibit remarkable designs with building blocks, often hierarchically arranged from the nanometer to the macroscopic length scales. We report on the structural properties of biosilica observed in the hexactinellid sponge Euplectella sp. Consolidated, nanometer-scaled silica spheres are arranged in well-defined microscopic concentric rings glued together by organic matrix to form laminated spicules. The assembly of these spicules into bundles, effected by the laminated silica-based cement, results in the formation of a macroscopic cylindrical square-lattice cagelike structure reinforced by diagonal ridges. The ensuing design overcomes the brittleness of its constituent material, glass, and shows outstanding mechanical rigidity and stability. The mechanical benefits of each of seven identified hierarchical levels and their comparison with common mechanical engineering strategies are discussed. Read more

Tunable Supercurrent Through Semiconductor Nanowires

by Yong-Joo Doh et al. Science, 8 Jul 2005 Nanoscale superconductor/semiconductor hybrid devices are assembled from indium arsenide semiconductor nanowires individually contacted by aluminum-based superconductor electrodes. Below 1 kelvin, the high transparency of the contacts gives rise to proximity-induced superconductivity. The nanowires form superconducting weak links operating as mesoscopic Josephson junctions with electrically tunable coupling. The supercurrent can be switched on/off by a gate voltage acting on the electron density in the nanowire. A variation in gate voltage induces universal fluctuations in the normal-state conductance, which are clearly correlated to critical current fluctuations. The alternating-current Josephson effect gives rise to Shapiro steps in the voltage-current characteristic under microwave irradiation. Read more

Single-Electron Delocalization in Hybrid Vertical-Lateral Double Quantum Dots

by T. Hatano, M. Stopa, & S. Tarucha1 Science, 8 Jul 2005 We used a hybrid vertical-lateral double-dot device, consisting of laterally coupled vertical quantum dots, to measure the interdot tunnel coupling. By using nonlinear transport measurements of "Coulomb diamonds," we showed that an inherent asymmetry in the capacitances of the component dots influences the diamond slopes, thereby allowing for the determination of the dot through which the electron has passed. We used this technique to prepare a delocalized one-electron state and Heitler-London (HL) two-electron state, and we showed that the interdot tunnel coupling, which determines whether HL is the ground state, is tunable. This implies that our device may be useful for implementing two-electron spin entanglement. Read more

Eternal Bits

by Mackenzie Smith IEEE Spectrum, July 2005 It took two centuries to fill the U.S. Library of Congress in Washington, D.C., with more than 29 million books and periodicals, 2.7 million recordings, 12 million photographs, 4.8 million maps, and 57 million manuscripts. Today it takes about 15 minutes for the world to churn out an equivalent amount of new digital information. It does so about 100 times every day, for a grand total of five exabytes annually. That’s an amount equal to all the words ever spoken by humans, according to Roy Williams, who heads the Center for Advanced Computing Research at the California Institute of Technology, in Pasadena. While this stunning proliferation of information underscores the ease with which we can create digital data, our capacity to make all these bits accessible in 200 or even 20 years remains a work in progress. Read more

Engineering EverQuest

by David Kushner IEEE Spectrum, July 2005 Up in the snow-covered hills, a guild of wizards and a group of blue-skinned dark elves close in on caves of ice. Inside lurk ominous frost spirits and who knows what other monsters in the shadows. The wizards summon their magic. The dark elves prepare for battle. It’s showdown time in Norrath. So let the data flow. After all, Norrath exists solely in the coded world of EverQuest, a best-selling computer game played over the Internet. As its often-fanatical devotees test their mettle in a rich fantasy world of fierce creatures, powerful servers and routers strive to keep up with them in humming computer rooms from California to South Korea. Read more

Education's Big Upgrade

by Jeff Yoders Building Design and Construction, June 2005 Forty-five percent of the country's elementary, middle, and high schools were built between 1950 and 1969 and will soon reach the end of their usefulness, according to the 2005–2008 K-12 School Market for Design & Construction Firms, published by ZweigWhite, a Massachusetts-based market-research firm. Almost 30% of U.S. schools were built before 1950 and need major modernization because enrollments continue to increase. Read more

Electronic Ears Give Police a Boost in Fighting Crime

by Megan Reichgott USATODAY.com, 5 Jul 2005 Police installed video surveillance cameras around town and saw Chicago's murder rate fall to its lowest level in four decades. Now the cops hope to further cut crime by not only watching, but listening, too. The city is employing new technology that recognizes the sound of a gunshot within a two-block radius, pinpoints the source, turns a surveillance camera toward the shooter and places a 911 call. Read more

Television That Leaps Off the Screen

by Michael Krantz New York Times, 3 Jul 2005 In a nondescript optics lab in tucked into an anonymous office park in the San Fernando Valley, the photon hackers of Deep Light are showing me the future of media. The object of their affection is a small screen on which an animated gladiator is clashing scimitars with a horned monster in a Coliseum-like setting. But this isn't a flat cartoon image: it's full 3-D space, the combatants circling each other inches from my eyes so convincingly that my hand twinges to grab them -- and I'm not wearing those clunky red-and-blue cardboard glasses, either. I'm seeing a 3-D image with the naked eye. Read more

Entering a Dark Age of Innovation

by Robert Adler NewScientist.com, 2 Jul 2005 Surfing the web and making free internet phone calls on your Wi-Fi laptop, listening to your iPod on the way home, it often seems that, technologically speaking, we are enjoying a golden age. Human inventiveness is so finely honed, and the globalised technology industries so productive, that there appears to be an invention to cater for every modern whim. But according to a new analysis, this view couldn't be more wrong: far from being in technological nirvana, we are fast approaching a new dark age. Read more

Robot Hand Performs Remote Breast Checks

by Will Knight NewScientist.com, 5 Jul 2005 Life-saving breast examinations could soon be performed by a robotic hand that combines ultrasound with an artificial sense of touch. The robotic breast examiner was devised by researchers at Michigan State University in the US. They say it will enable a medical specialist to examine women from a remote location, perhaps even from the other side of the world. Read more

Microwave Detection at 110 GHz by Nanowires with Broken Symmetry

by C. Balocco et al. Nano Letters, 7 Jun 2005 (web release) By using arrays of nanowires with intentionally broken symmetry, we were able to detect microwaves up to 110 GHz at room temperature. This is, to the best of our knowledge, the highest speed that has been demonstrated in different types of novel electronic nanostructures to date. Our experiments showed a rather stable detection sensitivity over a broad frequency range from 100 MHz to 110 GHz. The novel working principle enabled the nanowires to detect microwaves efficiently without a dc bias. In principle, the need for only one high-resolution lithography step and the planar architecture allow an arbitrary number of nanowires to be made by folding a linear array as many times as required over a large area, for example, a whole wafer. Our experiment on 18 parallel nanowires showed a sensitivity of approximately 75 mV dc output/mW of nominal input power of the 110 GHz signal, even though only about 0.4% of the rf power was effectively applied to the structure because of an impedance mismatch. Because this array of nanowires operates simultaneously, low detection noise was achieved, allowing us to detect -25 dBm 110 GHz microwaves at zero bias with a standard setup. Read more

Process vs. Density in DRAMs

by Geoff MacGillivray EE Times, 4 Jul 2005 The DRAM marketplace is one of the toughest markets in the semiconductor industry because margins are razor thin, even for the most cost-effective manufacturers. Therefore, DRAM makers must continually find ways to reduce cost while meeting market demands for larger memory densities and higher speeds. The most effective method available is to reduce die size through process shrinks and innovative design techniques such as 6F2 cell design. Read more

First Hydrogen Plane Tested in US

by Richard Black BBC News, 2 Jul 2005 A US company says it has successfully completed test flights of a potentially environment-friendly aircraft powered by liquid hydrogen. California-based AeroVironment says a full tank of hydrogen would keep the unmanned plane in the air for 24 hours. Read more

Hewlett Cites Progress on Quantum Computer

by John Markoff New York Times, 1 Jul 2005 Scientists at Hewlett-Packard said Thursday that they had developed a new strategy for designing a quantum computer composed of switches of light beams that could be vastly more powerful than today's digital electronic computers, which are constructed from transistors. Read more

Supercomputer for Dodgy Tickers

by Mark Baard Wired News, 1 Jul 2005 Doctors here in Beantown may soon turn to one of the world's fastest supercomputers as an aid to fixing bum tickers and removing formerly inoperable tumors. A new IBM BlueGene supercomputer, recently installed at Boston University, could give surgeons real-time, 3-D visualizations of patients' internal organs as they implant lifesaving devices or direct robotic instruments through tricky procedures, scientists said. Read more

Directed Self-Assembly of Spherical Particles on Patterned Electrodes by an Applied Electric Field

by A. Winkleman et al. Advanced Materials, 7 Jun 2005 Assembly techniques can produce patterns that would otherwise be difficult to make, but self-assembly processes can lack flexibility in the designs that can be produced. Our approach takes advantage of electrostatic forces to provide highly flexible patterns of glass microspheres. Patterns ranging from highly ordered arrays to arbitrary designs can be made, and in contrast to other such assembly techniques, it doesn't need to be carried out in solution. A polystyrene substrate is coated with layers of gold and chromium, which are then patterned with a self-assembled monolayer using microcontact printing. The areas of metal not protected by the monolayer are then etched to reveal windows of the substrate. When a high voltage is applied to the gold and the surface is flooded with glass microspheres, electrostatic forces ensure that one microsphere remains in each window, whilst tapping of the substrate minimizes defects. As this method doesn't rely on an assembly process between the microspheres, any pattern can be generated. Read more

Patent Highlights, 1 Jul 2005

optics.org News, 1 Jul 2005 The pick of this week’s patents including an optical system from Boeing for identifying seats. • OLED display having thermally conductive layer • Gas sensor • Apparatus and method for projecting identifying information onto seats Read the article

Nanotube Bike Enters Tour de France

by Liz Kalaugher nanotechweb.org News, 1 Jul 2005 This year’s Tour de France will see cyclists from the Phonak Team use a bike with a frame containing carbon nanotubes. Swiss manufacturer BMC claims that the frame of its "Pro Machine" weighs less than 1 kg and has excellent stiffness and strength. Read more

Silicon Nanowires as Enhancement-Mode Schottky Barrier Field-Effect Transistors

by Sang-Mo Koo et al. Nanotechnology, 29 Jun 2005 (web release) Silicon nanowire field-effect transistors (SiNWFETs) have been fabricated with a highly simplified integration scheme to function as Schottky barrier transistors with excellent enhancement-mode characteristics and a high on/off current ratio ~107. SiNWFETs show significant improvement in the thermal emission leakage (~6 × 10-13 A µm-1) compared to reference FETs with a larger channel width (~7 × 10-10 A µm-1). The drain current level depends substantially on the contact metal work function as determined by examining devices with different source/drain contacts of Ti (ap4.33 eV) and Cr (ap4.50 eV). The different conduction mechanisms for accumulation- and inversion-mode operation are discussed and compared with two-dimensional numerical simulation results. Read more http://www.iop.org/EJ/article/-search=9552754.1/0957-4484/16/9/011/nano5_9_011.pdf

Council Backs Huge Wind Farm Plan

BBC News, 30 Jun 2005 Plans to build the largest onshore wind farm in Europe have been approved by Comhairle nan Eilean Siar (Western Isles Council). An application by Lewis Wind Power for a 209 turbine wind farm in North Lewis, costing £400m, was passed by 19 votes to eight on Wednesday evening. Read more

'Clean Energy' Power Station Move

BBC News, 30 Jun 2005 The world's first industrial-scale clean energy power plant to generate "carbon-free" electricity from hydrogen could be built in Aberdeenshire. The £330m project will split natural gas into hydrogen and carbon dioxide. The hydrogen will fuel a new power station to be built near the existing power station at Peterhead. The carbon dioxide will then be liquefied and piped underground for storage in BP's Miller oil field where it can also help to recover more oil. Read more

Expanding the Molecular Electronics Toolbox

by Charles R. Martin & Lane A. Baker Science, 1 Jul 2005 Molecular electronics aims to build functional devices on the scale of individual molecules. The development of such devices requires accurate measurement and control of the electronic properties of individual molecules; in practice, this means that electrical "leads" must be attached to two ends of a molecule. Martin and Baker highlight a highly successful approach toward facilitating such measurements. The method, called on-wire lithography, yields nanowires with a gap into which a molecule can in principle be inserted. The method allows the size of the gap to be controlled with high accuracy, removing one obstacle to accurate single-molecule electrical measurements. Read more

On-Wire Lithography

by Lidong Qin et al. Science, 1 Jul 2005 We report a high-throughput procedure for lithographically processing one-dimensional nanowires. This procedure, termed on-wire lithography, combines advances in template-directed synthesis of nanowires with electrochemical deposition and wet-chemical etching and allows routine fabrication of face-to-face disk arrays and gap structures in the range of five to several hundred nanometers. We studied the transport properties of 13-nanometer gaps with and without nanoscopic amounts of conducting polymers deposited within by dip-pen nanolithography. Read more

What Are the Limits of Conventional Computing?

by Charles Seife Science, 1 Jul 2005 Mathematicians have shown that if you could come up with a quick and easy shortcut to solving any one of the hardest type of computational problems, you'd be able to crack them all. But it's uncertain whether such a shortcut exists. Scientists think not, but proving it is one of the great unanswered questions in mathematics. Read more