Measure of Metal Supply Finds Future Shortage

by David Biello ScientificAmerican.com, 17 Jan 2006 Copper is used in everything from automobiles to ordnance. Copper allows electricity to be generated, transported and conducted to the various outlets in a modern home. Copper is also relatively scarce compared to other metals like iron or aluminum that make up a good portion of the earth itself. So copper serves as an excellent metallic bellwether for potential future resource scarcity, according to a group of researchers who compiled data on its extraction, use, recycling and discard to estimate whether there is enough copper available to make a developed standard of living available to all the world's people. The short answer is: no. Read more

Thin Film Lithium Technology May Power Christmas of the Future

Oak Ridge National Laboratory News Release, 21 Dec 2005 Battery-powered toys, radios, and portable electronic devices make fun Christmas gifts -- until the batteries run down. But advances in rechargeable thin-film lithium battery technology at Oak Ridge National Laboratory might one day provide a solution to the dead-battery dilemma. Read more

Technology's 2006 Winners and Losers

This month, IEEE Spectrum magazine presents its third annual picks of the best and worst projects in technology. Winners include the Cell microprocessor and advances in LCD development, while losers include music-playing cell phones and Britain's national ID card. Also in this issue, the editors present seven more technologies that could eventually be winners or losers. Read more

The Impact of Digital TV on the Media Industry & Beyond

The first-ever comprehensive collection of digital television (DTV) tutorial papers has been published in the January 2006 issue of Proceedings of the IEEE. With contributions from international experts on DTV, the issue offers insight into the growing impact of digital television in two overview papers and in three special sections, which describe in detail each of the primary emerging DTV Systems that technically dominate North America, Europe and Japan. Read more

Geek Designer Wears Tech Well

by Leslie Katz ZDNet News, 24 Jan 2006 If you one day find yourself strutting down the street in an inflatable dress or peeking out from beneath a hood embedded with a digital camera, you may have Diana Eng to thank. Read more

Saddle Up Yer Velomobile

by Bryan Ball Wired News It's January and very cold in most of the northern hemisphere, but some innovative and persistent cyclists have found a way to keep pedaling even in the foulest weather. The human-powered vehicles they employ are called velomobiles -- fully enclosed recumbent bicycles that usually have three wheels, a chair-like seat and a standard bicycle drivetrain. The modern velomobile is the closest that anyone has come to building a truly practical all-weather, human-powered vehicle. Read more

High-Speed Microfluidic Differential Manometer for Cellular-Scale Hydrodynamics

by Manouk Abkarian, Magalie Faivre, & Howard A. Stone Proceedings of the National Academy of Sciences, 17 Jan 2006 We propose a broadly applicable high-speed microfluidic approach for measuring dynamical pressure-drop variations along a micrometer-sized channel and illustrate the potential of the technique by presenting measurements of the additional pressure drop produced at the scale of individual flowing cells. The influence of drug-modified mechanical properties of the cell membrane is shown. Finally, single hemolysis events during flow are recorded simultaneously with the critical pressure drop for the rupture of the membrane. This scale-independent measurement approach can be applied to any dynamical process or event that changes the hydrodynamic resistance of micro- or nanochannels. Read more

Jam-Avoiding Adaptive Cruise Control and Its Impact on Traffic Dynamics

by Arne Kesting et al. arXiv.org E-print Archive, 13 Jan 2006 Adaptive-Cruise Control (ACC) automatically accelerates or decelerates a vehicle to maintain a selected time gap, to reach a desired velocity, or to prevent a rear-end collision. To this end, the ACC sensors detect and track the vehicle ahead for measuring the actual distance and speed difference. Together with the own velocity, these input variables are exactly the same as in car-following models. The focus of this contribution is: What will be the impact of a spreading of ACC systems on the traffic dynamics? Do automated driving strategies have the potential to improve the capacity and stability of traffic flow or will they necessarily increase the heterogeneity and instability? How does the result depend on the ACC equipment level? We discuss microscopic modeling aspects for human and automated driving. By means of microscopic traffic simulations, we study how a variable percentage of ACC-equipped vehicles influences the stability of traffic flow, the maximum flow under free traffic conditions until traffic breaks down, and the dynamic capacity of congested traffic. Furthermore, we compare different percentages of ACC with respect to travel times in a specific congestion scenario. Remarkably, we find that already a small amount of ACC equipped cars and, hence, a marginally increased free and dynamic capacity, leads to a drastic reduction of traffic congestion. Read more

On the Mutual Coefficient of Restitution in Two Car Collinear Collisions

by Milan Batista arXiv.org E-print Archive, 21 Jan 2006 In the paper two car collinear collisions are discussed using Newton's law of mechanics, conservation of energy and linear constitutive law connecting impact force and crush. Two ways of calculating the mutual restitution coefficient are given: one already discussed by other authors that does not include the car's stiffness and a new one based on car stiffness. A numerical example of an actual test is provided. Read more

Mixing in Manipulated Turbulence

by Arkadiusz K. Kuczaj & Bernard J. Geurts arXiv.org E-print Archive, 21 Jan 2006 A new computational framework for the simulation of turbulent flow through complex objects and along irregular boundaries is presented. This is motivated by the application of metal foams in compact heat-transfer devices, or as catalyst substrates in process-engineering. The flow-consequences of such complicated objects are incorporated by adding explicit multiscale forcing to the Navier-Stokes equations. The forcing represents the simultaneous agitation of a wide spectrum of length-scales when flow passes through the complex object. It is found that a considerable modulation of the traditional energy cascading can be introduced with a specific forcing strategy. In spectral space, forcing yields strongly localized deviations from the common Kolmogorov scaling law, directly associated with the explicitly forced scales. In addition, the accumulated effect of forcing induces a significant non-local alteration of the kinetic energy including the spectrum for the large scales. Consequently, a manipulation of turbulent flow can be achieved over an extended range, well beyond the directly forced scales. The turbulent mixing of a passive scalar field is also investigated, in order to quantify the physical-space modifications of transport processes in multiscale forced turbulence. The surface-area and wrinkling of level-sets of the scalar field are monitored as measures of the influence of explicit forcing on the local and global mixing efficiency. Read more

'Precooling' Office Buildings Studied

PhysOrg.com, 23 Jan 2006 James Braun, a Purdue professor of mechanical engineering, said precooling would reduce energy consumption during times of peak demand, promising not only to save money but also to help prevent power failures during hot summer days. Read more

It May Look Authentic; Here's How to Tell It Isn't

by Nicholas Wade New York Times, 24 Jan 2006 Among the many temptations of the digital age, photo-manipulation has proved particularly troublesome for science, and scientific journals are beginning to respond. Some journal editors are considering adopting a test, in use at The Journal of Cell Biology, that could have caught the concocted images of the human embryonic stem cells made by Dr. Hwang Woo Suk. Read more

Super-Powerful New Ion Engine Revealed

by Emma Young NewScientist.com, 18 Jan 2006 A new design for an ion engine promises up to 10 times the fuel-efficiency of existing electric propulsion engines, according to tests by the European Space Agency. The new thruster could be used to propel craft into interstellar space, or to power a crewed mission to Mars, ESA says. Read more

Water Will 'Walk' Uphill under Its Own Steam

by Marcus Chown New Scientist, 21 Jan 2006 Liquid droplets have been made to "walk" across horizontal surfaces and even uphill -- quite literally under their own steam. Such self-propelled liquids could be used to cool microprocessors. Read more

Array Formation in Evanescent Waves

by Christopher D. Mellor & Dr., Colin. D. Bain ChemPhysChem, 27 Dec 2005 (published online) A form of matter held together by nothing more substantial than light has been created by physicists in the UK. The method, known as "optical binding", was used to glue together about 100 polystyrene beads in a flat two-dimensional structure. The phenomenon might one day provide a simple way to construct, or reconfigure, nanoscale structures. Read more

Spacecraft Skin 'Heals' Itself

by Will Knight NewScientist.com, 23 Jan 2006 A material that could enable spacecraft to automatically "heal" punctures and leaks is being tested in simulated space conditions on Earth. The self-healing spacecraft skin is being developed by Ian Bond and Richard Trask from the University of Bristol as part of a European Space Agency project. Read more

Einstein's 'Spooky Action' on a Chip

New Scientist, 14 Jan 2006 A simple semiconductor chip has been used to generate pairs of entangled photons, a vital step towards making quantum computers a reality. Famously dubbed "spooky action at a distance" by Einstein, entanglement is the mysterious phenomenon of quantum particles whereby two particles such as photons behave as one regardless of how far apart they are. Read more

The Attraction of Computing by Magnets

by Paul Marks New Scientist, 21 Jan 2006 As the transistors etched into computer chips approach their limits of miniaturisation over the coming years, they could be replaced by devices that use magnetism instead of electricity to store and manipulate digital data. Read more

Superplastic Carbon Nanotubes

by J. Y. Huang et al. Nature, 19 Jan 2006 The theoretical maximum tensile strain -- that is, elongation -- of a single-walled carbon nanotube is almost 20%, but in practice only 6% is achieved. Here we show that, at high temperatures, individual single-walled carbon nanotubes can undergo superplastic deformation, becoming nearly 280% longer and 15 times narrower before breaking. This superplastic deformation is the result of the nucleation and motion of kinks in the structure, and could prove useful in helping to strengthen and toughen ceramics and other nanocomposites at high temperatures. Read more

On the Mechanical Behavior of WS2 Nanotubes under Axial Tension and Compression

by Ifat Kaplan-Ashiri et al. Proceedings of the National Academy of Sciences, 17 Jan 2006 The mechanical properties of materials and particularly the strength are greatly affected by the presence of defects; therefore, the theoretical strength is not generally achievable for macroscopic objects. On the contrary, nanotubes, which are almost defect-free, should achieve the theoretical strength that would be reflected in superior mechanical properties. In this study, both tensile tests and buckling experiments of individual WS₂ nanotubes were carried out in a high-resolution scanning electron microscope. Tensile tests of MoS₂ nanotubes were simulated by means of a density-functional tight-binding-based molecular dynamics scheme as well. The combination of these studies provides a microscopic picture of the nature of the fracture process, giving insight to the strength and flexibility of the WS₂ nanotubes. Fracture analysis with recently proposed models indicates that the strength of such nanotubes is governed by a small number of defects. A fraction of the nanotubes attained the theoretical strength indicating absence of defects. Read more

Report Slams Impact of Nanotechnology Research

by John Walko EE Times, 24 Jan 2006 A market research group specializing in tracking developments in nanotechnology has hit out at the pace of commercialising the technology and the lack of commercial impact of nanotechnologies despite $18 billion of public funding since 1997. Read more

The Topology of Covert Conflict

by Shishir Nagarja arXiv.org E-print Archive, 23 Jan 2006 Often an attacker tries to disconnect a network by destroying nodes or edges, while the defender counters using various resilience mechanisms. Examples include a music industry body attempting to close down a peer-to-peer file-sharing network; medics attempting to halt the spread of an infectious disease by selective vaccination; and a police agency trying to decapitate a terrorist organisation. Albert, Jeong and Barabasi famously analysed the static case, and showed that vertex-order attacks are effective against scale-free networks. We extend this work to the dynamic case by developing a framework based on evolutionary game theory to explore the interaction of attack and defence strategies. We show, first, that naive defences don't work against vertex-order attack; second, that defences based on simple redundancy don't work much better, but that defences based on cliques work well; third, that attacks based on centrality work better against clique defences than vertex-order attacks do; and fourth, that defences based on complex strategies such as delegation plus clique resist centrality attacks better than simple clique defences. Our models thus build a bridge between network analysis and evolutionary game theory, and provide a framework for analysing defence and attack in networks where topology matters. They suggest definitions of efficiency of attack and defence, and may even explain the evolution of insurgent organisations from networks of cells to a more virtual leadership that facilitates operations rather than directing them. Finally, we draw some conclusions and present possible directions for future research. Read more

Energy Efficiency and Delay Quality-of-Service in Wireless Networks

by Farhad Meshkati et al. arXiv.org E-print Archive, 23 Jan 2006 The energy-delay tradeoffs in wireless networks are studied using a game-theoretic framework. A multi-class multiple-access network is considered in which users choose their transmit powers, and possibly transmission rates, in a distributed manner to maximize their own utilities while satisfying their delay quality-of-service (QoS) requirements. The utility function considered here measures the number of reliable bits transmitted per Joule of energy consumed and is particularly useful for energy-constrained networks. The Nash equilibrium solution for the proposed non-cooperative game is presented and closed-form expressions for the users' utilities at equilibrium are obtained. Based on this, the losses in energy efficiency and network capacity due to presence of delay-sensitive users are quantified. The analysis is extended to the scenario where the QoS requirements include both the average source rate and a bound on the average total delay. It is shown that the incoming traffic rate and the delay constraint of a user translate into a "size" for the user, which is an indication of the amount of resources consumed by the user. Using this framework, the tradeoffs among throughput, delay, network capacity and energy efficiency are also quantified. Read more

Stability of Scheduled Message Communication over Degraded Broadcast Channels

by KCV Kalyanarama Sesha Sayee & Utpal Mukherji arXiv.org E-print Archive, 22 Jan 2006 We consider scheduled message communication over a discrete memoryless degraded broadcast channel. The framework we consider here models both the random message arrivals and the subsequent reliable communication by suitably combining techniques from queuing theory and information theory. The channel from the transmitter to each of the receivers is quasi-static, flat, and with independent fades across the receivers. Requests for message transmissions are assumed to arrive according to an i.i.d. arrival process. Then, (i) we derive an outer bound to the region of message arrival vectors achievable by the class of stationary scheduling policies, (ii) we show for any message arrival vector that satisfies the outerbound, that there exists a stationary "state-independent" policy that results in a stable system for the corresponding message arrival process, and (iii) under two asymptotic regimes, we show that the stability region of nat arrival rate vectors has information-theoretic capacity region interpretation. Read more

Stability of Scheduled Multi-Access Communication over Quasi-Static Flat Fading Channels

by KCV Kalyanarama Sesha Sayee & Utpal Mukherji arXiv.org E-print Archive, 22 Jan 2006 We consider stability of scheduled multiaccess message communication with random coding and joint maximum-likehood decoding of messages. The framework we consider here models both the random message arrivals and the subsequent reliable communication by suitably combining techniques from queuing theory and information theory. The number of messages that may be scheduled for simultaneous transmission is limited to a given maximum value, and the channels from transmitters to receiver are quasi-static, flat, and have independent fades. Requests for message transmissions are assumed to arrive according to an i.i.d. arrival process. Then, (i) we derive an outer bound to the region of message arrival rate vectors achievable by the class of stationary scheduling policies, (ii) we show for any message arrival rate vector that satisfies the outerbound, that there exists a stationary state-independent policy that results in a stable system for the corresponding message arrival process, and (iii) in the limit of large message lengths, we show that the stability region of message nat arrival rate vectors has information-theoretic capacity region interpretation. Read more

LLL Reduction Achieves the Receive Diversity in MIMO Decoding

by Mahmoud Taherzadeh, Amin Mobasher, & Amir K. Khandani arXiv.org E-print Archive, 22 Jan 2006 Diversity order is an important measure for the performance of communication systems over multiple-input multiple-output (MIMO) fading channels. In this paper, we prove that in MIMO multiple access systems, lattice-reduction-aided decoding achieves the maximum receive diversity. Also, we prove that the naive lattice decoding achieves the maximum diversity. Read more

Communication Over MIMO Broadcast Channels Using Lattice-Basis Reduction

by Mahmoud Taherzadeh, Amin Mobasher, & Amir K. Khandani arXiv.org E-print Archive, 22 Jan 2006 A simple scheme for communication over multiple-input multiple-output (MIMO) broadcast channels is introduced which adopts the lattice reduction technique to improve the naive channel inversion method. Lattice basis reduction helps us to reduce the average transmitted energy by modifying the region which includes the constellation points. Simulation results show that the proposed scheme performs well, and as compared to the more complex methods has a negligible loss. Moreover, the proposed method is extended to the case of different rates for different users. The asymptotic behavior of the symbol error rate of the proposed method and the outage probability for the case of fixed-rate users are analyzed. It is shown that the proposed method achieves the optimum asymptotic slope of symbol-error-rate. Also, the outage probability for the case of fixed sum-rate is analyzed. Read more

Mobiles 'Don't Raise Cancer Risk'

BBC News, 20 Jan 2006 Mobile phone use does not lead to a greater risk of brain tumor, the largest study on the issue has said. The study of 2,782 people across the UK found no link between the risk of glioma -- the most common type of brain tumor -- and length of mobile use. Read more

Senators Announce Bipartisan National Innovation Act

Senators John Ensign (R-NV) and Joe Lieberman (D-CT) introduced the National Innovation Act last month that focuses on research investment, increasing science and technology talent and developing an innovation infrastructure to keep the United States in the lead in innovation. Highlights of the bill include:

• Establishing the Innovation Acceleration Grants Program which encourages federal agencies funding research in science and technology to allocate 3% of their Research and Development (R&D) budgets to grants directed toward high-risk frontier research.
• Increasing the national commitment to basic research by nearly doubling research funding for the National Science Foundation (NSF) by FY 2011.
• Making permanent the Research and Experimentation (R&E) tax credit with modifications expanding eligibility for incentives to a greater number of firms.
• Authorizing the Department of Defense to create a competitive traineeship program for undergraduate and graduate students in defense science and engineering that focuses on multidisciplinary learning and innovation-oriented studies.
• Authorizing funding for new and existing Professional Science Master’s Degree Programs to increase the number of qualified scientists and engineers entering the workforce.

Read more

Using DC-DC Converters in Mobile-Based Ground Equipment

by Tim Powers & Sean Penglase Military & Aerospace Electronics, December 2005 As designers incorporate increasing amounts of sophisticated electronics into industrial and military vehicle-based applications, high-density DC-DC converters have evolved to keep pace. Specifying a DC-DC converter that not only satisfies system requirements but also leverages performance improvements requires an understanding of converter capabilities and system requirements. The influence converters have on cost, performance, packaging and, above all, reliability, can be far-reaching. Designers must study and understand electrical emissions, cooling, mounting, and cabling. Read more

Networking Tomorrow’s Battlefields

by John McHale Military & Aerospace Electronics, December 2005 Defense planners today are planning tomorrow’s battles around the concept of a network-centric force by connecting all the elements-land, sea, air-into one networked force; the soldier sees what the pilots see, and what the sailors see. Key technologies include Internet Protocol, software-defined radio, and wireless networking. Read more

Researchers Seek Ways to Improve Lithium-Ion Batteries

Sandia National Laboratories News Release, 16 Jan 2006 As part of the Department of Energy-funded FreedomCAR program, Sandia National Laboratories’ Power Sources Technology Group is researching ways to make lithium-ion batteries work longer and safer. The research could lead to these batteries being used in new hybrid electric vehicles in the next five to ten years. Read more

Innovations from a Robot Rally

by W. Wayt Gibbs Scientific American, January 2006 This year's Grand Challenge competition sputted advances in laser sensing, computer vision and autonomous navigation-not to mention a thrilling race for the $2-million prize. Read more

Plasmonics: Merging Photonics and Electronics at Nanoscale Dimensions

by Ekmel Ozbay Science, 13 Jan 2006 Electronic circuits provide us with the ability to control the transport and storage of electrons. However, the performance of electronic circuits is now becoming rather limited when digital information needs to be sent from one point to another. Photonics offers an effective solution to this problem by implementing optical communication systems based on optical fibers and photonic circuits. Unfortunately, the micrometer-scale bulky components of photonics have limited the integration of these components into electronic chips, which are now measured in nanometers. Surface plasmon-based circuits, which merge electronics and photonics at the nanoscale, may offer a solution to this size-compatibility problem. Here we review the current status and future prospects of plasmonics in various applications including plasmonic chips, light generation, and nanolithography. Read more

Grain Boundary Strengthening in Alumina by Rare Earth Impurities

by J. P. Buban et al. Science, 13 Jan 2006 Impurity doping often alters or improves the properties of materials. In alumina, grain boundaries play a key role in deformation mechanisms, particularly in the phenomenon of grain boundary sliding during creep at high temperatures. We elucidated the atomic-scale structure in alumina grain boundaries and its relationship to the suppression of creep upon doping with yttrium by using atomic resolution microscopy and high-precision calculations. We find that the yttrium segregates to very localized regions along the grain boundary and alters the local bonding environment, thereby strengthening the boundary against mechanical creep. Read more

A Stretchable Form of Single-Crystal Silicon for High-Performance Electronics on Rubber Substrates

by Dahl-Young Khang et al. Science, 13 Jan 2006 We have produced a stretchable form of silicon that consists of submicrometer single-crystal elements structured into shapes with microscale, periodic, wavelike geometries. When supported by an elastomeric substrate, this "wavy" silicon can be reversibly stretched and compressed to large levels of strain without damaging the silicon. The amplitudes and periods of the waves change to accommodate these deformations, thereby avoiding substantial strains in the silicon itself. Dielectrics, patterns of dopants, electrodes, and other elements directly integrated with the silicon yield fully formed, high-performance "wavy" metal oxide semiconductor field-effect transistors, p-n diodes, and other devices for electronic circuits that can be stretched or compressed to similarly large levels of strain. Read more

Majority Logic Gate for Magnetic Quantum-Dot Cellular Automata

by A. Imre et al. Science, 13 Jan 2006 We describe the operation of, and demonstrate logic functionality in, networks of physically coupled, nanometer-scale magnets designed for digital computation in magnetic quantum-dot cellular automata (MQCA) systems. MQCA offer low power dissipation and high integration density of functional elements and operate at room temperature. The basic MQCA logic gate, that is, the three-input majority logic gate, is demonstrated. Read more

Quantum Dynamics of a d-Wave Josephson Junction

by Thilo Bauch et al. Science, 6 Jan 2006 Here we present the direct observation of macroscopic quantum properties in an all high-critical-temperature superconductor d-wave Josephson junction. Although dissipation caused by low-energy excitations is expected to strongly suppress macroscopic quantum effects, we demonstrate energy level quantization in our d-wave Josephson junction. The result indicates that the role of dissipation mechanisms in high-temperature superconductors has to be revised, and it may also have consequences for the class of solid-state "quiet" quantum bits with superior coherence time. Read more

Researchers to Develop Nano-Size Battery to be Implanted in Eye

PhysOrg.com, 12 Jan 2006 Several researchers from Sandia National Laboratories, led by principal investigator Susan Rempe, are part of a multi-institutional, multidisciplinary team developing a nano-size battery that one day could be implanted in the eye to power an artificial retina. Read more

A Semiconductor Source of Triggered Entangled Photon Pairs

by R. M. Stevenson et al. Nature, 12 Jan 2006 Entangled photon pairs are an important resource in quantum optics, and are essential for quantum information applications such as quantum key distribution and controlled quantum logic operations. The radiative decay of biexcitons -- that is, states consisting of two bound electron-hole pairs -- in a quantum dot has been proposed as a source of triggered polarization-entangled photon pairs. To date, however, experiments have indicated that a splitting of the intermediate exciton energy yields only classically correlated emission. Here we demonstrate triggered photon pair emission from single quantum dots suggestive of polarization entanglement. We achieve this by tuning the splitting to zero, through either application of an in-plane magnetic field or careful control of growth conditions. Entangled photon pairs generated 'on demand' have significant fundamental advantages over other schemes, which can suffer from multiple pair emission, or require post-selection techniques or the use of photon-number discriminating detectors. Furthermore, control over the pair generation time is essential for scaling many quantum information schemes beyond a few gates. Our results suggest that a triggered entangled photon pair source could be implemented by a simple semiconductor light-emitting diode. Read more

Use of Highly-Ordered TiO2 Nanotube Arrays in Dye-Sensitized Solar Cells

by Gopal K. Mor et al. Nano Letters, 31 Dec 2005 (Web Release) We describe the use of highly ordered transparent TiO2 nanotube arrays in dye-sensitized solar cells (DSCs). Highly ordered nanotube arrays of 46-nm pore diameter, 17-nm wall thickness, and 360-nm length were grown perpendicular to a fluorine-doped tin oxide-coated glass substrate by anodic oxidation of a titanium thin film. After crystallization by an oxygen anneal, the nanotube arrays are treated with TiCl₄ to enhance the photogenerated current and then integrated into the DSC structure using a commercially available ruthenium-based dye. Although the negative electrode is only 360-nm-thick, under AM 1.5 illumination the generated photocurrent is 7.87 mA/cm², with a photocurrent efficiency of 2.9%. Voltage-decay measurements indicate that the highly ordered TiO2 nanotube arrays, in comparison to nanoparticulate systems, have superior electron lifetimes and provide excellent pathways for electron percolation. Our results indicate that remarkable photoconversion efficiencies may be obtained, possibly to the ideal limit of ~31% for a single photosystem scheme, with an increase of the nanotube-array length to several micrometers. Read more

Optical Wireless and Broadband over Power Lines

Penn State Public release date: 11 Jan 2006 Penn State engineers have shown that a white-LED system for lighting and high data-rate indoor wireless communications, coupled with broadband over either medium- or low-voltage power line grids, can offer transmission capacities that exceed DSL or cable and are more secure than RF. Read more

Engineers Create Mathematical Method to Design Better Robots, Structures

Purdue University Public release date: 11 Jan 2006 Mechanical and civil engineers have created a new mathematical method to design better structures, machines and versatile computer-controlled robots called "robot manipulators." Read more

Groups Set to Approve Next-Gen Wi-Fi Spec

by John Walko EE Times, 12 Jan 2006 The industry is honing in on a compromise proposal for the contentious IEEE 802.11n next generation WLAN standard, and a deal could be struck next week at the task group’s meeting in Hawaii. Read more

Zeno Machines and Hypercomputation

by Petrus H. Potgieter arXiv.org E-print Archive, 11 Jan 2006 This paper reviews the Church-Turing Thesis (or rather, theses) with reference to their origin and application and considers some models of "hypercomputation", concentrating on perhaps the most straight-forward option: Zeno machines (Turing machines with accelerating clock). The halting problem is briefly discussed in a general context and the suggestion that it is an inevitable companion of any reasonable computational model is emphasised. It is hinted that claims to have "broken the Turing barrier" could be toned down and that the important and well-founded role of Turing computability in the mathematical sciences stands unchallenged. Read more

Toshiba Claims Entangled Photon Breakthrough

by Rupert Goodwins ZDNet News, 11 Jan 2006 Researchers at Cambridge University and Toshiba have announced a new quantum device that produces entangled photons, a promising technology for quantum encryption. Consisting of pairs of photons of light whose fundamental properties are inextricably linked, the technology has attracted increasing interest over the past 10 years. It has many possible uses in addition to encryption, including communications, quantum computing, medical imaging and chip production. Read more

Bus Data Detects Traffic Snarls

by Joanna Glasner Wired News, 11 Jan 2006 For commuters, it's a common but aggravating scenario. You speed down the highway, comforted by radio reports that traffic is flowing smoothly. Then you get off the exit ramp and find cars jammed to a crawl. Today, freeway commuters have access to a wealth of up-to-the-minute data they can use to avoid traffic. But for drivers on major commercial thoroughfares, gridlock information is limited. Seattle transportation researchers are trying to make travel on these arterial routes more predictable by using data collected from city buses. Read more

The Ultimate Geek Car?

by Bruce Gain Wired News, 11 Jan 2006 Mercedes-Benz probably didn't have the geek set in mind when it designed its new flagship 2007 S-Class sedan. But when the luxury car hits U.S. streets in February, it'll be packing a bundle of electronics that would make David Hasselhoff green with envy. An onboard radar system, automated acceleration and braking controls, and a night-vision display are among the features that Mercedes describes as the most advanced available in cars today. Read more

Spin Doctors Create Quantum Chip

by John Hudson Wired News, 11 Jan 2006 University of Michigan scientists have created the first quantum microchip, which could be a giant stride in the race to produce a new generation of brawny, super-fast computers. Read more

Don't Swat That Fly - It's a Spacecraft!

by Peter N. Spotts USATODAY.com, 11 Jan 2006 Picture this: Swarms of one-legged robots hopping across Mars like malformed chicks. They dart in and out of caves and crevices, grabbing soil samples and searching for signs of ancient microbes -- and thus life. Or this: A flying wing that gently flaps across the cloud tops of Venus, sniffing the atmosphere for organic molecules. Elsewhere in the solar system, robots that buzz and flit like insects will hover over planets, hunting for hot spots formed by lava or exploring crater walls. Welcome to the space exploration of tomorrow. Read more

Clever Car Keeps an Eye on Stray Pedestrians

by Will Knight NewScientist.com, 12 Jan 2006 A prototype vehicle capable of spotting pedestrians who stray into the road has been built by Volkswagen and other companies. The pedestrian-recognition technology uses three different types of sensor to identify a person, or even a cyclist, in the road ahead. Read more

NSF Program Solicitation - Scholarships in Science, Technology, Engineering, and Mathematics

This program makes grants to institutions of higher education to support scholarships for academically talented, financially needy students, enabling them to enter the workforce following completion of an associate, baccalaureate, or graduate level degree in science and engineering disciplines. Grantee institutions are responsible for selecting scholarship recipients, reporting demographic information about student scholars, and managing the S-STEM project at the institution. Read more

NSF Program Solicitation - Ethics Education in Science and Engineering

The Ethics Education in Science and Engineering program considers proposals for research and educational projects to improve ethics education in all of the fields of science and engineering that NSF supports. For this year, proposals must focus on improving ethics education for graduate students in those fields, and on ethical issues that arise in research or graduate research education in those fields, particularly in interdisciplinary or inter-institutional contexts. Read more

'Quiet' Mach 6 Wind Tunnel Helps Shape Future Aircraft

Public release date: 5 Jan 2006 Purdue University Purdue University engineers have developed a wind tunnel that is the only one of its kind in the world capable of running quietly at "hypersonic" speeds, helping researchers to design advanced aircraft and missiles. No other wind tunnel runs quietly while conducting experiments in airstreams traveling at Mach 6 -- six times the speed of sound. Read more

Car Make, Age and Fuel Economy All Affect How Much Vehicles Pollute

Ohio State University Public release date: 9 Jan 2006 When it comes to how much automobiles pollute, some makes are cleaner than others, according to new research. While other studies have analyzed data from state emissions tests, this is the first time that researchers examined how different car makes compared. The study also found that the vehicles that polluted the most tended to be those that were older models, had higher mileage, poorer fuel economy, and were less-well-maintained. Read more

New Football Helmet Design May Reduce Concussions

University of Pittsburgh Medical Center Public release date: 9 Jan 2006 Newer football helmet technology and design may reduce the incidence of concussions in high school football players, according to results from the first phase of a three-year study by the University of Pittsburgh Medical Center's Sports Medicine Concussion Program. The current study compared concussion rates and recovery times of high school athletes wearing newer helmet technology to those wearing helmets with traditional designs. Read more

Geopolymers with the Potential for Use as Refractory Castables

by Dan S Perera & Rachael L Trautman AZojomo, 2 Jan 2006 A geopolymer was prepared by dissolving metakaolinite in a solution of K₂SiO₃ and KOH and curing at 80°C for 24 h. It was progressively heated from ambient to 1400°C in air and the phase changes were studied by X-ray diffraction analysis, scanning electron microscopy and energy dispersive X-ray spectroscopy. Only an amorphous geopolymer phase was observed on heating up to 800°C. Kalsilite was the major phase at 1000°C and 1250-1400°C. At 1200°C leucite was the major phase formed. At 1400°C there was no sign of significant melting. The open porosity of the material was ~ 38% at 1000°C, which is sufficiently porous for it to be used as a heat insulation material for continuous use at this temperature. Read more

Prop-Based Haptic Interaction with Co-location and Immersion: an Automotive Application

by Michael Ortega & Sabine Coquillart arXiv.org E-print Archive, 9 Jan 2006 Most research on 3D user interfaces aims at providing only a single sensory modality. One challenge is to integrate several sensory modalities into a seamless system while preserving each modality's immersion and performance factors. This paper concerns manipulation tasks and proposes a visuo-haptic system integrating immersive visualization, tactile force and tactile feedback with co-location. An industrial application is presented. Read more

On the Fading Number of Multiple-Input Single-Output Fading Channels with Memory

by Stefan M. Moser arXiv.org E-print Archive, 9 Jan 2006 We derive new upper and lower bounds on the fading number of multiple-input single-output (MISO) fading channels of general (not necessarily Gaussian) regular law with spatial and temporal memory. The fading number is the second term, after the double-logarithmic term, of the high signal-to-noise ratio (SNR) expansion of channel capacity. In case of an isotropically distributed fading vector it is proven that the upper and lower bound coincide, i.e., the general MISO fading number with memory is known precisely. The upper and lower bounds show that a type of beam-forming is asymptotically optimal. Read more

Lighting Control using Pressure-Sensitive Touchpads

by Alexander Haubold arXiv.org E-print Archive, 7 Jan 2006 We introduce a novel approach to control physical lighting parameters by means of a pressure-sensitive touchpad. The two-dimensional area of the touchpad is subdivided into 5 virtual sliders, each controlling the intensity of a color (red, green, blue, yellow, and white). The physical interaction methodology is modeled directly after ubiquitous mechanical sliders and dimmers which tend to be used for intensity/volume control. Our abstraction to a pressure-sensitive touchpad provides advantages and introduces additional benefits over such existing devices. Read more

Better Robots Could Help Save Disaster Victims

by Kurt Kleiner NewScientist.com, 5 Jan 2006 In the wake of the tragic accident that killed 12 trapped miners in West Virginia, roboticists are saying that a new generation of search-and rescue-robots could help save lives in future disasters. Read more

Structural Diversity in Binary Nanoparticle Superlattices

by Elena V. Shevchenko et al. Nature, 5 Jan 2006 Assembly of small building blocks such as atoms, molecules and nanoparticles into macroscopic structures -- that is, 'bottom up' assembly -- is a theme that runs through chemistry, biology and material science. Bacteria, macromolecules, and nanoparticles can self-assemble, generating ordered structures with a precision that challenges current lithographic techniques. The assembly of nanoparticles of two different materials into a binary nanoparticle superlattice (BNSL) can provide a general and inexpensive path to a large variety of materials (metamaterials) with precisely controlled chemical composition and tight placement of the components. Maximization of the nanoparticle packing density has been proposed as the driving force for BNSL formation, and only a few BNSL structures have been predicted to be thermodynamically stable. Recently, colloidal crystals with micrometre-scale lattice spacings have been grown from oppositely charged polymethyl methacrylate spheres. Here we demonstrate formation of more than 15 different BNSL structures, using combinations of semiconducting, metallic and magnetic nanoparticle building blocks. At least ten of these colloidal crystalline structures have not been reported previously. We demonstrate that electrical charges on sterically stabilized nanoparticles determine BNSL stoichiometry; additional contributions from entropic, van der Waals, steric and dipolar forces stabilize the variety of BNSL structures. Read more

GigaBeam Unveils Ultra-Fast Broadband Radio

by Doug Lockie fibers.org News, 5 Jan 2006 The cost of deploying fiber to the premise limits the data rates available to most US businesses. The solution is to connect fiber networks to enterprises by millimeter-wave radio transmissions, delivering gigabit-per-second data rates. Read more

Nanocrystals Eyed as Solar Cell Material

by Dylan McGrath EE Times, 4 Jan 2006 Carrier multiplication, a phenomenon in which semiconductor nanocrystals respond to photons by producing multiple electrons, is applicable to a broader array of materials than previously thought, according to scientists at Los Alamos National Laboratory. Read more

Semiconductor Roadmap Updated - with 2005 Version

by Peter Clarke EE Times, 5 Jan 2006 The latest edition of the International Technology Roadmap for Semiconductors is now available online. However, despite the fact that we have just moved into 2006 the latest version of the ITRS is the 2005 edition. Read more

Stabilization of a Linear System over a Noisy Communication Link, Part I

by Anant Sahai & Sanjoy Mitter arXiv.org E-print Archive, 4 Jan 2006 We review how Shannon's classical notion of capacity is not enough to characterize a noisy communication channel if the channel is intended to be used as part of a feedback loop to stabilize an unstable scalar linear system. While classical capacity is not enough, another sense of capacity (parametrized by reliability) called "anytime capacity"' is shown to be necessary for the stabilization of an unstable process. The required rate is given by the log of the unstable system gain and the required reliability comes from the sense of stability desired. A consequence of this necessity result is a sequential generalization of the Schalkwijk/Kailath scheme for communication over the AWGN channel with feedback. In cases of sufficiently rich information patterns between the encoder and decoder, adequate anytime capacity is also shown to be sufficient for there to exist a stabilizing controller. These sufficiency results are then generalized to cases with noisy observations, delayed control actions, and without any explicit feedback between the observer and the controller. Both necessary and sufficient conditions are extended to continuous time systems as well. We close with comments discussing a hierarchy of difficulty for communication problems and how these results establish where stabilization problems sit in that hierarchy. Read more

From Electronics to Anyonics

by Frank Wilczek Physics World, January 2006 Particles called anyons that do not fit into the usual categories of fermions and bosons may lead to high-performance quantum computers. Read more

Ions Trapped on a Chip

by Belle Dumé physicsweb.org News, 13 Dec 2005 By encoding information in the quantum states of subatomic particles, quantum computers have the potential to make the latest Pentium chip look as outmoded as the abacus. But before such a device can even begin to compete with its classical counterpart, we need to first find a way to scale-up individual quantum "bits." Now, physicists in the US have made an important step towards this goal by creating an ion trap on a semiconductor chip. Such microscale traps could allow many qubits to be integrated in a workable quantum computer. Read more

Negative Refraction in Ferromagnet-Superconductor Superlattices

by A. Pimenov et al. Physical Review Letters, 9 Dec 2005 Negative refraction, which reverses many fundamental aspects of classical optics, can be obtained in systems with negative magnetic permeability and negative dielectric permittivity. This Letter documents an experimental realization of negative refraction at millimeter waves, finite magnetic fields, and cryogenic temperatures utilizing a multilayer stack of ferromagnetic and superconducting thin films. In the present case the superconducting YBa₂Cu₃O₇ layers provide negative permittivity while negative permeability is achieved via ferromagnetic (La:Sr)MnO₃ layers for frequencies and magnetic fields close to the ferromagnetic resonance. In these superlattices the refractive index can be switched between positive and negative regions using external magnetic field as tuning parameter. Read more

General Stability Criterion of Two-Dimensional Inviscid Parallel Flow

by Liang Sun arXiv.org E-print Archive, 27 Dec 2005 General stability criterions of two-dimensional inviscid parallel flow are obtained analytically for the first time. First, a criterion for stability is found everywhere in the flow. Second, we also prove a principle that the flow is stable, if and only if all the disturbances are neutrally stable. Finally, following this principle, a criterion for instability is found everywhere in the flow. These results extend the former theorems obtained by Rayleigh, Tollmien and Fjørtoft and will lead future works to investigate the mechanism of hydrodynamic instability. Read more

Intrinsic Geometric Structure of Turbulent Flow for Newton Fluid

by Jianhua Xiao arXiv.org E-print Archive, 3 Jan 2006 Many researches show that the complicated motion of fluid, such as turbulence, cannot be well solved by the Navier-Stokes equation. Chen Zida has founded that the definition of vortex, based on the Stokes decomposition, cannot well describe the local rotation when the velocity gradient is highly asymmetric. Chen reformulates the Stokes S+R decomposition into a general S+R decomposition. By further extending Chen results, this research studies the motion equation of fluid for the case where highly asymmetric velocity gradient is exhibited. The result shows that the classical NS equation does not meet the requirement of angular momentum conservation, which is apparently ignored for infinitesimal velocity gradient of fluid. This paper reformulates the intrinsic geometric description of fluid motion and two additional equations are introduced. Combining with the classical NS equation, the reformulated motion equations are in closed-form. The research shows that the NS equation is good approximation for average flow, so it can not solve the turbulent problem in essential sense. However, this conclusion does not deny that with suitable additional condition for special engineering problem it is still a would-be acceptable approximation. Read more

A Step Closer to Quantum Supercomputers

PhysOrg.com, 4 Jan 2006 Oxford scientists have come a step closer to quantum ‘supercomputers’ by creating a new technique called ‘bang-bang’ to hold quantum information. Read more

Displays That Give a Clear View

PhysOrg.com, 4 Jan 2006 Displays made of organic LEDs are brightly lit but tend to be mostly opaque. Making them transparent opens up a whole new world of applications: OLEDs can be wedded with conventional LCDs and transform laminated glass into a display panel. Read more

Brakes That Pay Attention When the Driver Doesn't

by Tara Baukus Mello New York Times, 2 Jan 2006 After years of concentrating their efforts on reducing injuries caused by collisions, auto engineers are increasingly turning their attention to what happens in the moments before an impact. Stability control systems have become ever more capable of catching spins before they end in a crash; brakes can now be programmed to recognize panic stops and apply maximum force for hesitant drivers. Read more

Cars Are Talking - Safety Is the Topic

by Jeremy W. Peters New York Times, 2 Jan 2006 The technology that took control to prevent a crash is an example of the next-generation collision-avoidance systems that automakers are increasingly developing. Read more

Hybrids, Hydrogen and Hype

by James G. Cobb New York Times, 1 Jan 2006 The hybrid car has been around for years, but in 2005 it went mainstream. Still, fuel-cell cars face huge hurdles. Read more

Buzzing Buttons Cancel Car Noise

New Scientist, 7 Jan 2006 Dozens of vibrating buttons dotted around cars could give passengers a quieter ride. Attached to components around the vehicle, the coin-sized buttons will cancel out the vibrations that cause much of the noise inside a typical car. Read more

Spring-Loaded Microbe Inspires Nanomachines

by Peter Aldhous New Scientist, 17 Dec 2005 The scum-dwelling beast boasts a tiny spring that, for its size, is more powerful than a car engine -- bioengineers hope to use similar springs in nanodevices. Read more

Generation of Hyperentangled Photon Pairs

by Julio T. Barreiro et al. Physical Review Letters, 31 Dec 2005 We experimentally demonstrate the first quantum system entangled in every degree of freedom (hyperentangled). Using pairs of photons produced in spontaneous parametric down-conversion, we verify entanglement by observing a Bell-type inequality violation in each degree of freedom: polarization, spatial mode, and time energy. We also produce and characterize maximally hyperentangled states and novel states simultaneously exhibiting both quantum and classical correlations. Finally, we report the tomography of a 2×2×3×3 system (36-dimensional Hilbert space), which we believe is the first reported photonic entangled system of this size to be so characterized. Read more

Why a Robot is Better with One Eye Than Two

by Celeste Biever New Scientist, 17 Dec 2005 Most robots are horribly short-sighted. Beyond a few metres, everything in their field of vision merges into the background, so that instead of steering a smooth path through the landscape they bumble around from one obstacle to the next. Now a type of vision system has been developed to make robots more agile. And unlike conventional robot vision systems, it works with just one cheap camera instead of two. Read more

Innovation: Pick of the Latest Patent Applications

fibers.org, 12 Dec 2005 Joe McEntee reveals his pick of the latest patent applications in the field of optical networking.

• POF connections eye cable TV services
• Low-speed components, high-speed transmission
• Expand capacity without shutting down the traffic
• RF optical system makes remote power redundant
• Mode-noise averaging will enhance multimode links
• Light-emitting materials yield silicon compatibility
• Compact transceiver will suit portable computing
• Dynamic compensation eases signal degradation
• Evolutionary scheme aids upgrades of legacy PONs

Read more

Engineering: Is the U.S. Really Falling?

by Pete Engardio BusinessWeek Online, 27 Dec 2005 Is America losing its competitive edge in engineering? Top Silicon Valley executives, U.S. think-tanks, industry associations, and university deans have all pointed out dropping enrollment in American science and tech programs and warn of a brewing problem. And in a November survey of 4,000 U.S. engineers, 64% said outsourcing makes them worry about the profession's future, while less than 10% feel sure America will maintain its leadership in technology. Read more

High-Speed Fabric Backplanes Burst on the Scene in a Data-Hungry World

by John Keller Military & Aerospace Electronics, December 2005 The new generation of high-speed fabric data backplanes represent a fundamental paradigm shift in technology that not only offers dramatic increases in data bandwidth, but also may be as significant as the shift from analog to digital signals. Read more