Navy Developing Nanotech to Improve Ships

CNN.com, accessed 31 May 2006 With an eye to developing faster ships, the U.S. Navy has teamed up with a New York company and the University at Albany's College of Nanoscale Science and Engineering to develop an electronics system that will sharply reduce the size and weight of a warship's motors. Read more

Rubber Highway to Beat Congestion

by Jonathan Fildes BBC News, 31 May 2006 A congestion-beating project that could lead to some of the UK's 9,000 miles of disused railway being paved with rubber, has been launched. The flexible highways are made of panels of shredded car tyres laid over the existing tracks. Read more

Researchers Build Electronic Functions inside Fibre

by Belle Dumé fibers.org News, 31 May 2006 Optical fibres are the established platform for communications technology and semiconductor devices are commonly used in microelectronics. Now, scientists at Southampton University and Penn State University have developed a new way to combine these two technologies. The novel technique, which allows electronic functions to be built directly into a microstructured optical fibre, could extend optoelectronics well beyond what is currently achieved in planar semiconductor waveguide devices. Read more

IEEE-USA President Urges Concerted, Sustained Action on Adoption of "New Internet"

IEEE-USA News Release, 24 May 2006 Just as "visionaries" of the Age of Enlightenment in 18th century Europe pursued progress through rationality, the developers of the 21st Century's "New Internet" will "benefit the public good by balancing the needs of users and society," said Dr. Ralph W. Wyndrum, Jr., IEEE-USA's 2006 President, addressing some 125 attendees at the Federal IPv6 Summit in Reston, VA. Read more

Carbon Nanotubes as High-Pressure Cylinders and Nanoextruders

by L. Sun et al. Science, 26 May 2006 Closed-shell carbon nanostructures, such as carbon onions, have been shown to act as self-contracting high-pressure cells under electron irradiation. Controlled irradiation of multiwalled carbon nanotubes can cause large pressure buildup within the nanotube cores that can plastically deform, extrude, and break solid materials that are encapsulated inside the core. We further showed by atomistic simulations that the internal pressure inside nanotubes can reach values higher than 40 gigapascals. Nanotubes can thus be used as robust nanoscale jigs for extruding and deforming hard nanomaterials and for modifying their properties, as well as templates for the study of individual nanometer-sized crystals under high pressure. Read more

Growing Glowing Nanowires to Light Up the Nanoworld

National Institute of Standards and Technology Public Release, 25 May 2006 The nano world is getting brighter. Nanowires made of semiconductor materials are being used to make prototype lasers and light-emitting diodes with emission apertures roughly 100 nm in diameter -- about 50 times narrower than conventional counterparts. Nanolight sources may have many applications, including "lab on a chip" devices for identifying chemicals and biological agents, scanning-probe microscope tips for imaging objects smaller than is currently possible, or ultra-precise tools for laser surgery and electronics manufacturing. Read more

Researchers Selected to Improve Military Armor

Virginia Tech Public Release, 24 May 2006 Virginia Tech has been selected by the Army Research Laboratory to establish a Materials Center of Excellence. The center will develop polymer-based materials to protect personnel and equipment against weapons attack. The center will also offer graduate student and postdoctoral scholar mentorship and undergraduate research programs. Read more

Virtual Coordinate Backtracking for Void Traversal in Geographic Routing

by Ke Liu & Nael Abu-Ghazaleh arXiv.org E-print Archive, 30 May 2006 Geographical routing protocols have several desirable features for use in ad hoc and sensor networks but are susceptible to voids and localization errors. Virtual coordinate systems are an alternative solution to geographically based routing protocols that works by overlaying a coordinate system on the sensors relative to well chosen reference points. VC is resilient to localization errors; however, we show that it is vulnerable to different forms of the void problem and have no viable complementary approach to overcome them. Specifically, we show that there are instances when packets reach nodes with no viable next hop nodes in the forwarding set. In addition, it is possible for nodes with the same coordinates to arise at different points in the network in the presence of voids. This paper identifies and analyzes these problems. It also compares several existing routing protocols based on Virtual Coordinate systems. Finally, it presents a new routing algorithm that uses backtracking to overcome voids to achieve high connectivity in the greedy phase, higher overall path quality and more resilience to localization errors. We show these properties using extensive simulation analysis. Read more

Memory Aware High-Level Synthesis for Embedded Systems

by Gwenolé Corre et al. arXiv.org E-print Archive, 30 May 2006 We introduce a new approach to take into account the memory architecture and the memory mapping in the High- Level Synthesis of Real-Time embedded systems. We formalize the memory mapping as a set of constraints used in the scheduling step. We use a memory mapping file to include those memory constraints in our HLS tool GAUT. Our scheduling algorithm exhibits a relatively low complexity that permits to tackle complex designs in a reasonable time. Finally, we show how to explore, with the help of GAUT, a wide range of solutions, and to reach a good tradeoff between time, power-consumption, and area. Read more

High-Level Synthesis under I/O Timing and Memory Constraints

by Philippe Coussy et al. arXiv.org E-print Archive, 30 May 2006 The design of complex Systems-on-Chips implies to take into account communication and memory access constraints for the integration of dedicated hardware accelerator. We present a methodology and a tool that allow the High-Level Synthesis of DSP algorithm, under both I/O timing and memory constraints. Based on formal models and a generic architecture, this tool helps the designer to find a reasonable trade-off between both the required I/O timing behavior and the internal memory access parallelism of the circuit. The interest of our approach is demonstrated on the case study of a FFT algorithm. Read more

General Compact Labeling Schemes for Dynamic Trees

by Amos Korman arXiv.org E-print Archive, 30 May 2006 Let F be a function on pairs of vertices. An F- labeling scheme is composed of a marker algorithm for labeling the vertices of a graph with short labels, coupled with a decoder algorithm allowing one to compute F(u, v) of any two vertices u and v directly from their labels. As applications for labeling schemes concern mainly large and dynamically changing networks, it is of interest to study distributed dynamic labeling schemes. This paper investigates labeling schemes for dynamic trees. We consider two dynamic tree models, namely, the leaf-dynamic tree model in which at each step a leaf can be added to or removed from the tree and the leaf-increasing tree model in which the only topological event that may occur is that a leaf joins the tree. Read more

DSR with Non-Optimal Route Suppression for MANETs

by Boon-Chong Seet, Bu-Sung Lee, & Chiew-Tong Lau arXiv.org E-print Archive, 29 May 2006 This paper revisits the issue of route discovery in dynamic source routing (DSR) for mobile ad hoc networks (MANETs), and puts forward a proposal of a lightweight non-optimal route suppression technique based on the observation of a rarely noted but commonly occurring phenomenon in route discovery. The technique exploits the observed phenomenon to extract query state information that permits intermediate nodes to identify and suppress the initiation of route replies with non-optimal routes, even if the route query is received for the first time. A detailed evaluation of DSR with non-optimal route suppression is found to yield significant improvements in both protocol efficiency and performance. Read more

New AccessScience Article - Fire Safety (Building Design)

by Prof. Jat-Yuen Richard Liew & H.X. Yu National University of Singapore Department of Civil Engineering Gain a better understanding of the design issues faced by architects and engineers as they construct our public buildings and work spaces. Safety considerations including evacuation procedures, fire modeling, and heat transfer analysis are discussed. Read article

Optical Conformal Mapping

by Ulf Leonhardt Science, 26 May 2006 An invisibility device should guide light around an object as if nothing were there, regardless of where the light comes from. Ideal invisibility devices are impossible due to the wave nature of light. This paper develops a general recipe for the design of media that create perfect invisibility within the accuracy of geometrical optics. The imperfections of invisibility can be made arbitrarily small to hide objects that are much larger than the wavelength. Using modern metamaterials, practical demonstrations of such devices may be possible. The method developed here can be also applied to escape detection by other electromagnetic waves or sound. Read more

Controlling Electromagnetic Fields

by J. B. Pendry, D. Schurig, & D. R. Smith Science, 25 May 2006 Using the freedom of design that metamaterials provide, we show how electromagnetic fields can be redirected at will and propose a design strategy. The conserved fields -- electric displacement field D, magnetic induction field B, and Poynting vector S -- are all displaced in a consistent manner. A simple illustration is given of the cloaking of a proscribed volume of space to exclude completely all electromagnetic fields. Our work has relevance to exotic lens design and to the cloaking of objects from electromagnetic fields. Read more

DoE Funding Opportunity - Computational Methodologies to Design, Engineer, and Evaluate Materials for Fossil Energy Applications

Novel materials that can withstand high temperatures and extreme environments, as well as those needed for the separation and storage of hydrogen are dominant themes in materials development for efficient energy systems. For the former, basic requirements are elevated melting temperatures, high oxidation and corrosion resistance, the ability to resist creep, and high toughness. Obtaining these properties encompass some of the most challenging problems in materials science. Computer simulation to study the structure, properties, and processing of materials on the atomic scale is needed to speed the advancement of innovative strategies that would replace traditional, trial-and-error experimental methods which are costly and time-consuming. A wide range of computer modeling tools, ranging from highly accurate quantum mechanics (electronic structure) methods to simple interatomic potentials, could be brought to bear on addressing critical materials needs. Experimental verification and testing in combination with computational approaches is desirable. Read more

DoE Funding Opportunity - Instrumentation, Sensors, and Control Systems

Computational Approaches for the Design of Sensor Networks and Process Control for Coal Gasification or Oxygen Enhanced Combustion Systems - (A) Modeling and simulation of coal gasifiers and oxygen enhanced combustion systems are under development to aid in the design and evaluation of these systems and plants. This topic seeks to extend or develop additional computational capabilities that will facilitate the analysis and design of sensor and control systems that enable these power systems. The development of these tools and analysis must consider the performance goals and constraints of the power system/plant. Two primary challenges of these systems are the desire to be fuel flexible and responsive to load changes. Attention to sensor type, placement, and number of sensors as well as the approach for control of the system are important factors for inclusion in the computationally-based research. (B) Instrumentation and sensors play a key role in describing a process or system. In the case of advanced coal-fired power generation systems, select instrumentation and sensors are not available to provide the data needed to describe or anticipate process changes. This subtopic seeks development of novel approaches for those measurements that are viewed to be of broad interest and high priority. Specifically, developments for on-line/at-line analytical techniques for coal quality and/or flow rate are sought. Read more

DoD Funding Opportunity - Information Theory for Mobile Ad-Hoc Networks for Young Investigators

The objective of the Information Theory for Mobile Ad-Hoc Networks program is to generate and exploit superior theoretical insights concerning the design, deployment, and operation of a new generation of wireless mobile networks. To achieve this objective, a central challenge problem has been devised: to close a longstanding open problem concerning the capacity limits of Mobile Ad-hoc NETworks. The central program thesis is that a novel kind of information theory -- one powerful enough to address the challenge problem -- will have wide-ranging practical consequences in the long term. Specifically, it is believed that capacity understanding in relation to necessary trades has immediate application, and moreover that new architectures and protocols will emerge as a side-effect of developing the techniques needed for capacity understanding. Residual knowledge generated by researchers who fully engage in this challenge problem will serve the national interest in progress toward more ubiquitous, reliable, and trustworthy communication systems. Read more

DOE Funding Opportunity - Collaborative Energy Efficiency Research in Iron-Making and Steel-Making

The solicitation seeks to develop transformational ironmaking and steelmaking processes to reduce the energy intensity of the steel industry. The technical areas of interest are as follows: (1) new or improved alternative ironmaking technologies, including Direct Reduced Iron technologies, and new steelmaking technologies that significantly reduce the use of energy, (2) technologies to improve the energy efficiency of equipment currently used in the most energy-intensive process steps of blast furnace ironmaking, scrap melting, and reheating, (3) technologies to minimize the generation of scrap and oxides, including improved processes for recovering and upgrading low-grade scrap, (4) applicants may also submit proposals for analytical studies on the issues of displacing natural gas in ironmaking by the gasification of alternative fuels. Read more

Brain Waves Make Robot Move

Associated Press WIred News, 24 May 2006 Japanese automaker Honda has developed technology that uses brain signals to control a robot's moves, hoping to someday link a person's thoughts with machines in everyday life. In the future, the technology that Honda Motor researched with ATR Computational Neuroscience Laboratories may substitute for a keyboard or cell phone or help people with spinal injuries move their limbs, researchers said Wednesday. Read more

Ge/Si Nanowire Heterostructures as Aigh-Performance Field-Effect Transistors

by Jie Xiang et al. Nature, 25 May 2006 Semiconducting carbon nanotubes and nanowires are potential alternatives to planar metal-oxide-semiconductor field-effect transistors (MOSFETs) owing, for example, to their unique electronic structure and reduced carrier scattering caused by one-dimensional quantum confinement effects. Studies have demonstrated long carrier mean free paths at room temperature in both carbon nanotubes and Ge/Si core/shell nanowires. In the case of carbon nanotube FETs, devices have been fabricated that work close to the ballistic limit. Applications of high-performance carbon nanotube FETs have been hindered, however, by difficulties in producing uniform semiconducting nanotubes, a factor not limiting nanowires, which have been prepared with reproducible electronic properties in high yield as required for large-scale integrated systems. Yet whether nanowire field-effect transistors (NWFETs) can indeed outperform their planar counterparts is still unclear. Here we report studies on Ge/Si core/shell nanowire heterostructures configured as FETs using high- dielectrics in a top-gate geometry. The clean one-dimensional hole-gas in the Ge/Si nanowire heterostructures and enhanced gate coupling with high- dielectrics give high-performance FETs values of the scaled transconductance (3.3 mS m-1) and on-current (2.1 mA m-1) that are three to four times greater than state-of-the-art MOSFETs and are the highest obtained on NWFETs. Furthermore, comparison of the intrinsic switching delay, = CV/I, which represents a key metric for device applications shows that the performance of Ge/Si NWFETs is comparable to similar length carbon nanotube FETs and substantially exceeds the length-dependent scaling of planar silicon MOSFETs. Read more

From a Poet's Failing Sight, a Novel 'Seeing Machine' Emerges

by Denise Grady New York Times, 23 May 2006 A poet and artist has enlisted the help of scientists and engineering students to create a "seeing machine" that may eventually help people like her, with severely impaired vision, to read, look at pictures and explore landscapes and buildings. Read more

MIT Material Puts New Spin on Electronics

Massachusetts Institute of Technology Public Release date, 24 May 2006 Researchers at MIT's Francis Bitter Magnet Lab have developed a novel magnetic semiconductor that may greatly increase the computing power and flexibility of future electronic devices while dramatically reducing their power consumption. The new material is a significant step forward in the field of spin-based electronics -- or "spintronics" -- where the spin state of electrons is exploited to carry, manipulate and store information. Read more

A Tiny, Self-Powered Sensor

University of Florida Public Release, 24 May 2006 Hydrogen has been called "the fuel of the future." But the gas is invisible, odorless and explosive at high concentrations, posing a safety problem for hydrogen-powered cars, filling stations and other aspects of the so-called hydrogen economy. Now, a team of more than a dozen University of Florida engineering faculty and graduate students has found a way to jump that hurdle: a tiny, inexpensive sensor device that can detect hydrogen leaks and sound the alarm by wireless communication. Read more

IEEE Wireless Communications Addresses Mesh Networking

The April issue of IEEE Wireless Communications (v. 13, no. 2) takes an in-depth look at the subject of Wireless Mesh Networking. Topics include mesh WLAN networks, smart antennas, and standards and security issues. IEEE Wireless Communications

Large Scale Flow Effects, Energy Transfer, and Self-Similarity on Turbulence

by P.D. Mininni, A. Alexakis, & A. Pouquet arXiv.org E-print Archive, 19 May 2006 The effect of large scales on the statistics and dynamics of turbulent fluctuations is studied using data from high resolution direct numerical simulations. Three different kinds of forcing, and spatial resolutions ranging from 256^3 to 1024^3, are being used. The study is carried out by investigating the nonlinear triadic interactions in Fourier space, transfer functions, structure functions, and probability density functions. Our results show that the large scale flow plays an important role in the development and the statistical properties of the small scale turbulence. The role of helicity is also investigated. We discuss the link between these findings and intermittency, deviations from universality, and possible origins of the bottleneck effect. Finally, we briefly describe the consequences of our results for the subgrid modeling of turbulent flows. Read more

To the Fluid Motion Dynamics

by S. L. Arsenjev arXiv.org E-print Archive, 19 May 2006 A fluid motion through the flow element is presented in the kind of an autooscillating system with the distributed parameters: mass, elasticity, viscosity. The system contains a self-excited oscillator and possesses a self-regulation on base of the intrinsic voluntary negative servo output feedback. The interaction dynamics of the submerged jet, out-flowing out of a flow element, with the homogeneous for it surrounding medium as well as dynamics of evolution of the spiral-vortex structures, appearing at the relative motion of fluids, are described for the first time. The conceptual model of a flow in the kind of the completed system of the cause and effect relationship, that presents the fluid motion process as a result in interaction of the motive power, applied from without, and the internal wave mechanism, selfregulating the flow structure and its intensity, is created. Read more

Observation of Brewster's Effect for Transverse-Electric Electromagnetic Waves in Metamaterials

by Y. Tamayama Physical Review B, 17 May 2006 We have experimentally realized Brewster's effect for transverse-electric waves with metamaterials. In dielectric media, Brewster's no-reflection effect arises only for transverse-magnetic waves. However, it has been theoretically predicted that Brewster's effect arises for TE waves under the condition that the relative permeability µr is not equal to unity. We have designed an array of split-ring resonators as a metamaterial with µr ≠ 1 using a finite-difference time-domain method. The reflection measurements were carried out in a 3-GHz region and the disappearance of reflected waves at a particular incident angle was confirmed. Read more

Coupled Applications on Distributed Resources

by P. V. Coveney et la. arXiv.org E-print Archive, 19 May 2006 Coupled models are set to become increasingly important in all aspects of science and engineering as tools with which to study complex systems in an integrated manner. Such coupled, hybrid simulations typically communicate data between the component models of which they are comprised relatively infrequently, and so a Grid is expected to present an ideal architecture on which to run them. We describe a simple, flexible and extensible architecture for a two-component hybrid molecular-continuum coupled model. We discuss its deployment on distributed resources and the extensions to the RealityGrid computational-steering system to handle coupled models. Read more

Essence of Inviscid Shear Instability: A Point View of Vortex Dynamics

by Liang Sun arXiv.org E-print Archive, 19 May 2006 The essence of shear instability is fully revealed both mathematically and physically. A general sufficient and necessary stable criterion is obtained analytically within linear context. It is the analogue of Kelvin-Arnol'd theorem, i.e., the stable flow minimizes the kinetic energy associated with vorticity. Then the mechanism of shear instability is explored by combining the mechanisms of both Kelvin-Helmholtz instability and resonance of waves. It requires both concentrated vortex and resonant waves for the instability. The waves, which have same phase speed with the concentrated vortex, have interactions with the vortex to trigger the instability. We call this mechanism as "concentrated vortex instability." The physical explanation of shear instability is also sketched. Finally, some useful criteria are derived from the theorem. These results would intrigue future works to investigate the other hydrodynamic instabilities. Read more

An Optically Activated Cantilever Using Photomechanical Effects in Dye-Doped Polymer Fibers

by Shaoping Bian, Dirk Robinson, & Mark G. Kuzyk arXiv.org E-print Archive, 18 May 2006 We report on what we believe is the first demonstration of an optically activated cantilever due to photomechanical effects in a dye-doped polymer optical fiber. The fiber is observed to bend when light is launched off-axis. The displacement angle monotonically increases as a function of the distance between the illumination point and the fiber axis, and is consistent with differential light-induced length changes. The photothermal and photo-reorientation mechanisms, each with its own distinct response time, are proposed to explain the observed time dependence. The measured degree of bending is consistent with a model that we have proposed which includes coupling between photoisomerization and heating. Most importantly, we have discovered that at high light intensity, a cooperative release of stress results in cis-to-trans isomerization that yields a large and abrupt length change. Read more

All-Optical Switching, Bistability, and Slow-Light Transmission in Photonic Crystal Waveguide-Resonator Structures

by Sergei F. Mingaleev et al. arXiv.org E-print Archive, 18 May 2006 We analyze the resonant linear and nonlinear transmission through a photonic crystal waveguide side-coupled to a Kerr-nonlinear photonic crystal resonator. Firstly, we extend the standard coupled-mode theory analysis to photonic crystal structures and obtain explicit analytical expressions for the bistability thresholds and transmission coefficients which provide the basis for a detailed understanding of the possibilities associated with these structures. Next, we discuss limitations of standard coupled-mode theory and present an alternative analytical approach based on the effective discrete equations derived using a Green's function method. We find that the discrete nature of the photonic crystal waveguides allows a novel, geometry-driven enhancement of nonlinear effects by shifting the resonator location relative to the waveguide, thus providing an additional control of resonant waveguide transmission and Fano resonances. We further demonstrate that this enhancement may result in the lowering of the bistability threshold and switching power of nonlinear devices by several orders of magnitude. Finally, we show that employing such enhancements is of paramount importance for the design of all-optical devices based on slow-light photonic crystal waveguides. Read more

London Looks at Car Speed Limiters

BBC News, 23 May 2006 Transport for London (TfL) has said it is working on a system which could automatically reduce a vehicle's speed. But TfL said the Intelligent Speed Adaptation scheme is only being considered for public vehicles such as buses and taxis. Read more

Can Engine Make Gas Obsolete?

Wired News, 20 May 2006 While much of the world fumes over escalating fuel prices, a small company in north central Iowa is quietly hoping to make gasoline obsolete as an engine fuel. Research at the Hydrogen Engine Center is done in an early 1900s red brick armory at the Kossuth County fairgrounds. There, a clean six-cylinder engine that looks like it could have been pulled from a Ford pickup has been running for 110 hours, not quite half the 300 hours it must continuously run for certification. Read more

Space Elevator - Going Down?

news@nature.com, 22 May 2006 by Jason Palmer Is it possible to make a cable for a space elevator out of carbon nanotubes? Not anytime soon, if ever, says Nicola Pugno of the Polytechnic of Turin, Italy. Pugno's calculations show that inevitable defects in the nanotubes mean that such a cable simply wouldn't be strong enough. Read more

Hydrogen Fuel Balls

by Barry Fox NewScientist.com, 22 May 2006 Hydrogen is often promoted as an ideal clean fuel for cars. But the explosive stuff is also darned dangerous to transport and store. So the U.S. Department of Energy has been looking for ways to make it as safe and easy to pump as gasoline. The solution, according to one of its latest patent applications, could be to store it in tiny glass balls. The proposed glass microspheres would each be a few millionths of a metre wide with a hollow centre containing specks of palladium. The walls of each sphere would also have pores just a few ten-billionths of a metre in diameter. Placing the microspheres in a tank filled with hydrogen gas under pressure should cause the gas to seep through the pores to be absorbed by the palladium. The spheres could then be used to safely store and transport the hydrogen, which could be sucked back out using heat or vacuum pressure. The glass spheres should be so small and slippery that they ought to flow through pipes like a liquid, the patent says. In addition, the hydrogen should be so tightly locked inside the spheres that there would be no risk of explosion or fire if a leak occurs. Read patent

Nuclear Fusion Plasma Problem Tackled

by Kurt Kleiner NewScientist.com, 22 May 2006 Nuclear fusion could become a more viable energy solution with the discovery of way to prevent super-hot gases from causing damage within reactors. The potential solution, tested at an experimental reactor in San Diego, US, could make the next generation of fusion reactors more efficient, saving hundreds of millions of euros a year. Read more

How Our Body's Defences Aid Computers in Distress

by Duncan Graham-Rowe New Scientist, 19 May 2006 The way the body's immune system responds when its cells are under attack has inspired a new way of protecting computer networks from viruses and hackers. An intrusion detection system for networks that listens for distress signals from besieged computers is being developed by a team led by computer scientist Uwe Aickelin at the University of Nottingham in the UK. It is designed to offer networks better protection from the ravages of email viruses and denial of service attacks, and in tests has already defended a network against simulated hacker attacks. Read more

An Aluminium Nitride LED with a Wavelength of 210 Nanometres

by Yoshitaka Taniyasu, Makoto Kasu, & Toshiki Makimoto Nature, 18 May 2006 Compact high-efficiency ultraviolet solid-state light sources -- such as light-emitting diodes (LEDs) and laser diodes -- are of considerable technological interest as alternatives to large, toxic, low-efficiency gas lasers and mercury lamps. Microelectronic fabrication technologies and the environmental sciences both require light sources with shorter emission wavelengths: the former for improved resolution in photolithography and the latter for sensors that can detect minute hazardous particles. In addition, ultraviolet solid-state light sources are also attracting attention for potential applications in high-density optical data storage, biomedical research, water and air purification, and sterilization. Wide-bandgap materials, such as diamond and III–V nitride semiconductors, are potential materials for ultraviolet LEDs and laser diodes, but suffer from difficulties in controlling electrical conduction. Here we report the successful control of both n-type and p-type doping in aluminium nitride (AlN), which has a very wide direct bandgap of 6 eV. This doping strategy allows us to develop an AlN PIN (p-type/intrinsic/n-type) homojunction LED with an emission wavelength of 210 nm, which is the shortest reported to date for any kind of LED. The emission is attributed to an exciton transition, and represents an important step towards achieving exciton-related light-emitting devices as well as replacing gas light sources with solid-state light sources. Read more

When Is a Metal Not a Metal?

by Steven C. Erwin Nature, 18 May 2006 Every student knows the difference between a metal and an insulator: one conducts electricity and the other doesn't. Things get more interesting if you ask how this difference arises. Although the question is disarmingly simple, a rigorous answer was not available until about 1930, when Felix Bloch and Alan Wilson used the new quantum mechanics to create a theory that distinguished metals from insulators. The spectacular success of this 'band theory of solids', as it is now known, has made it a cornerstone of the modern theory of solids. In a few glaring cases, however, band theory doesn't get it right. Read more

Carbon Nanotube Sheets as Electrodes in Organic Light-Emitting Diodes

by C. M. Aguirre et al. Applied Physics Letters, 1 May 2006 High performance organic light-emitting diodes (OLEDs) were implemented on transparent and conductive single-wall carbon nanotube sheets. At the maximum achieved brightness of 2800 cd m^–2 the luminance efficiency of our carbon nanotube-based OLED is 1.4 cd A^–1 which is comparable to the 1.9 cd A^–1 measured for an optimized indium tin oxide anode device made under the same experimental conditions. A thin parylene buffer layer between the carbon nanotube anode and the hole transport layer is required in order to readily achieve the measured performance. Read more

Custom Made Micronized Silica For Paint Industry Via Fine Grinding Process

by Samayamutthirian Palaniandy et al. Azojomo, 2 May 2006 The paint industry demands stringent filler specifications. Custom made mineral fillers with improvement in terms of particle size and shape during the fine grinding process will enhance the paint quality. An experimental work was carried out by varying the classifier speed of a jet mill to improve the particle size and particle morphology while the grinding pressure was kept constant. The control of the fine grinding process was essential as the classifier speed influenced the ground product in terms of particle size and shape. The highest circularity index, 0.962 was obtained at 10000 rpm with a smooth surface texture and trimmed sharp edges which fulfils the filler specification of the paint industry. Read more

Energy System Revamped for More Fuel-Efficient Cars

Massachusetts Institute of Technology Public Release, 22 May 2006 MIT researchers are trying to unleash the promise of an old idea by converting light into electricity more efficiently than ever before. The research is applying new materials, new technologies and new ideas to radically improve an old concept -- thermophotovoltaic (TPV) conversion of light into electricity. Rather than using the engine to turn a generator or alternator in a car, for example, the new TPV system would burn a little fuel to create super-bright light. Efficient photo diodes would then harvest the energy and send the electricity off to run the various lighting, electrical and electronic systems in the car. Read more

Fast Mass Transport Through Sub-2-Nanometer Carbon Nanotubes

by Jason K. Holt et al. Science, 19 May 2006 We report gas and water flow measurements through microfabricated membranes in which aligned carbon nanotubes with diameters of less than 2 nanometers serve as pores. The measured gas flow exceeds predictions of the Knudsen diffusion model by more than an order of magnitude. The measured water flow exceeds values calculated from continuum hydrodynamics models by more than three orders of magnitude and is comparable to flow rates extrapolated from molecular dynamics simulations. The gas and water permeabilities of these nanotube-based membranes are several orders of magnitude higher than those of commercial polycarbonate membranes, despite having pore sizes an order of magnitude smaller. These membranes enable fundamental studies of mass transport in confined environments, as well as more energy-efficient nanoscale filtration. Read more

Students Design Deep-Sea Explorer to Search for Lake Ontario Shipwrecks

Rochester Institute of Technology Public Release, 19 May 2006 It's designed to explore the depths of large bodies of water -- and one recent weekend, that's exactly where it was found: searching the depths of the deep end of Judson Pool in Rochester Institute of Technology's Gordon Field House and Activities Center. A team of RIT engineering majors built the explorer, an underwater remote-operated vehicle, or ROV -- and it has been described as one of the most ambitious student projects ever at RIT. This spring and summer, the device will be used to explore century-old shipwrecks resting on the bottom of Lake Ontario and the Atlantic Ocean -- giving human explorers their first glimpses of some all-but-forgotten vessels lost to the seas. Read more

Desorption of H from Si(111) by Resonant Excitation of the Si-H Vibrational Stretch Mode

by Zhiheng Liu et al. Science, 19 May 2006 Past efforts to achieve selective bond scission by vibrational excitation have been thwarted by energy thermalization. Here we report resonant photodesorption of hydrogen from a Si(111) surface using tunable infrared radiation. The wavelength dependence of the desorption yield peaks at 0.26 electron volt: the energy of the Si-H vibrational stretch mode. The desorption yield is quadratic in the infrared intensity. A strong H/D isotope effect rules out thermal desorption mechanisms, and electronic effects are not applicable in this low-energy regime. A molecular mechanism accounting for the desorption event remains elusive. Read more

New Solutions for World's Energy Woes

Florida State University Public Release, 22 May 2006 Approximately 2 billion of the world's people -- nearly one-third of the human population -- have no access to electricity. Consequently, they do without many of the amenities that people in the developed world take for granted -- everything from air conditioning and refrigeration to television, indoor lighting, and pumps that supply drinking water. And without electricity to power factory operations or other commercial endeavors, those 2 billion people remain mired in an endless cycle of poverty. One Florida State University researcher is working to break that cycle through the development of new energy technologies that are easy to install, environmentally sound and -- perhaps most importantly -- inexpensive to produce. Read more

Homogeneity in Sintering of Fine Ni-20Cr Powder by Pulsed Electric Current Sintering Process

by Manabu Sato et al. Azojomo, 2 May 2006 Homogeneity of porous Ni-20Cr bodies made of powders with 5 mm and 70 mm in particle size fabricated by pulsed electric current sintering (PECS) was investigated by means of microstructure observation. Porous samples made of fine powder by PECS had a microstructure with the interior significantly denser than the surface region. The heterogeneous structure is caused by temperature distribution generated due to self-heating of sample by Joule heating and heat transfer from sample to die. Use of a die with thicker die wall gives homogeneous sintered bodies. Read more

U.S. Engineers Competitive vs. China, India

by Sheila Riley EE Times, 22 May 2006 U.S. engineers are holding their own, at least for now, compared with their counterparts in China and India. So concludes Duke University testimony presented this month to Congress’ Committee on Education and the Workforce. Read more

Roadblocks Seen in Immersion Lithography

by Mark LaPedus EE Times, 19 May 2006 There is a growing sentiment that high refractive index materials for 193-nm immersion lithography are not panning out, thereby implying that immersion will run out of gas at the 32-nm node. Read more

Sending a Bi-Variate Gaussian Source over a Gaussian MAC

by Amos Lapidoth & Stephan Tinguely arXiv.org E-print Archive, 22 May 2006 We consider a problem where a memoryless bi-variate Gaussian source is to be transmitted over an additive white Gaussian multiple-access channel with two transmitting terminals and one receiving terminal. The first transmitter only sees the first source component and the second transmitter only sees the second source component. We are interested in the pair of mean squared-error distortions at which the receiving terminal can reproduce each of the source components. It is demonstrated that in the symmetric case, below a certain signal-to-noise ratio (SNR) threshold, which is determined by the source correlation, uncoded communication is optimal. For SNRs above this threshold we present outer and inner bounds on the achievable distortions. Read more

Energy Efficiency in Multi-hop CDMA Networks: A Game Theoretic Analysis

by Sharon Betz & H. Vincent Poor arXiv.org E-orint Archive, 22 May 2006 A game-theoretic analysis is used to study the effects of receiver choice on the energy efficiency of multi-hop networks in which the nodes communicate using Direct-Sequence Code Division Multiple Access. A Nash equilibrium of the game in which the network nodes can choose their receivers as well as their transmit powers to maximize the total number of bits they transmit per unit of energy is derived. The energy efficiencies resulting from the use of different linear multiuser receivers in this context are compared, looking at both the non-cooperative game and the Pareto optimal solution. For analytical ease, particular attention is paid to asymptotically large networks. Significant gains in energy efficiency are observed when multiuser receivers, particularly the linear minimum mean-square error receiver, are used instead of conventional matched filter receivers. Read more

The Capacity of the Single Source Multiple Relay Single Destination Mesh Network

by Lawrence Ong & Mehul Motani arXiv.org E-print Archive, 22 May 2006 In this paper, we derive the capacity of a special class of mesh networks. A mesh network is defined as a heterogeneous wireless network in which the transmission among power limited nodes is assisted by powerful relays, which use the same wireless medium. We find the capacity of the mesh network when there is one source, one destination, and multiple relays. We call this channel the single source multiple relay single destination mesh network. Our approach is as follows. We first look at an upper bound on the information theoretic capacity of these networks in the Gaussian setting. We then show that the bound is achievable asymptotically using the compress-forward strategy for the multiple relay channel. Theoretically, the results indicate the value of cooperation and the utility of carefully deployed relays in wireless ad-hoc and sensor networks. The capacity characterization quantifies how the relays can be used to either conserve node energy or to increase transmission rate. Read more

The Multiple Access Channel with Feedback and Correlated Sources

by Lawrence Ong & Mehul Motani arXiv.org E-print Archive, 22 May 2006 In this paper, we investigate communication strategies for the multiple access channel with feedback and correlated sources (MACFCS). The MACFCS models a wireless sensor network scenario in which sensors distributed throughout an arbitrary random field collect correlated measurements and transmit them to a common sink. We derive achievable rate regions for the three-node MACFCS. First, we study the strategy when source coding and channel coding are combined, which we term full decoding at sources. Second, we look at several strategies when source coding and channel coding are separated, which we term full decoding at destination. From numerical computations on Gaussian channels, we see that different strategies perform better under certain source correlations and channel setups. Read more

Traffic-Analysis Reslient MAC Protocol for Multi-Hop Wireless Networks

by Ke Liu, Adnan Majeed & Nael B. Abu-Ghazaleh arXiv.org, 19 May 2006 Traffic analysis in Multi-hop Wireless Networks can expose the structure of the network allowing attackers to focus their efforts on critical nodes. For example, jamming the only data sink in a sensor network can cripple the network. We propose a new communication protocol that is part of the MAC layer, but resides conceptually between the routing layer and MAC, that is resilient to traffic analysis. Each node broadcasts the data that it has to transmit according to a fixed transmission schedule that is independent of the traffic being generated, making the network immune to time correlation analysis. The transmission pattern is identical, with the exception of a possible time shift, at all nodes, removing spatial correlation of transmissions to network strucutre. Data for all neighbors resides in the same encrypted packet. Each neighbor then decides which subset of the data in a packet to forward onwards using a routing protocol whose details are orthogonal to the proposed scheme. We analyze the basic scheme, exploring the tradeoffs in terms of frequency of transmission and packet size. We also explore adaptive and time changing patterns and analyze their performance under a number of representative scenarios. Read more

Error Exponents and Cutoff Rate for Noncoherent Rician Fading Channels

by Mustafa Cenk Gursoy arXiv.org E-print Archive, 19 May 2006 In this paper, random coding error exponents and cutoff rate are studied for noncoherent Rician fading channels, where neither the receiver nor the transmitter has channel side information. First, it is assumed that the input is subject only to an average power constraint. In this case, a lower bound to the random coding error exponent is considered and the optimal input achieving this lower bound is shown to have a discrete amplitude and uniform phase. If the input is subject to both average and peak power constraints, it is proven that the optimal input achieving the random coding error exponent has again a discrete nature. Finally, the cutoff rate is analyzed, and the optimality of the single-mass input amplitude distribution in the low-power regime is discussed. Read more

A Locating-First Approach for Scalable Overlay Multicast

by Mohamed Ali Dali Kaafar, Thierry Turletti, & Walid Dabbous arXiv.org E-print Archive, 18 May 2006 Recent proposals in multicast overlay construction have demonstrated the importance of exploiting underlying network topology. However, these topology-aware proposals often rely on incremental and periodic refinements to improve the system performance. These approaches are therefore neither scalable, as they induce high communication cost due to refinement overhead, nor efficient because long convergence time is necessary to obtain a stabilized structure. We propose a highly scalable locating algorithm that gradually directs newcomers to their a set of their closest nodes without inducing high overhead. On the basis of this locating process, we build a robust and scalable topology-aware clustered hierarchical overlay scheme, called LCC. We conducted both simulations and PlanetLab experiments to evaluate the performance of LCC. Results show that the locating process entails modest resources in terms of time and bandwidth. Moreover, LCC demonstrates promising performance to support large scale multicast applications. Read more

On the Capacity of Fading MIMO Broadcast Channels

by Amos Lapidoth, Shlomo Shamai, & Michele Wigger arXiv.org E-print Archive, 17 May 2006 A fading broadcast channel is considered where the transmitter employs two antennas and each of the two receivers employs a single receive antenna. It is demonstrated that even if the realization of the fading is precisely known to the receivers, the high signal-to-noise throughput is greatly reduced if, rather than knowing the fading realization precisely, the trasmitter only knows the fading realization approximately. The results are general and are not limited to memoryless Gaussian fading. Read more

Scientists Back Plug-In Hybrids

by Ken Thomas USATODAY.com, 17 May 2006 A group of scientists urged Congress on Wednesday to fund research for plug-in hybrid vehicles, touting the technology as another way to reduce the nation's dependence on oil through the help of a simple electrical socket. Read more

Slowing Light in Optical Fibres Sees Fast Progress

by Luc Thévenaz & Miguel Gonzalez-Herraez fibers.org News, 18 May 2006 The ability to temporarily store a signal and recall it at an exact point in time is an essential function of any type of signal processing system. The development of all-optical signal processing has been seriously impaired due to the lack of timing tools. But as we advance towards all-optical systems, this situation must improve if we are to avoid bottlenecks in data transmission and routing. Read more

Curve Shortening and the Rendezvous Problem for Mobile Autonomous Robots

by Stephen L. Smith et al. arXiv.org E-print Archive, 16 May 2006 If a smooth, closed, and embedded curve is deformed along its normal vector field at a rate proportional to its curvature, it shrinks to a circular point. This curve evolution is called Euclidean curve shortening and the result is known as the Gage-Hamilton-Grayson Theorem. Motivated by the rendezvous problem for mobile autonomous robots, we address the problem of creating a polygon shortening flow. A linear scheme is proposed that exhibits several analogues to Euclidean curve shortening: the polygon shrinks to an elliptical point, convex polygons remain convex, and the perimeter of the polygon is monotonically decreasing. Read more

Programmable Antifuses Enabled through Sandia-Developed Dielectric Thin Film

Sandia National Laboratories Press Release, 15 May 2006 Researchers at Sandia National Laboratories have developed an inexpensive, reliable and easy-to-manufacture class of dielectric films that have the capability of enabling programmable antifuses on integrated circuits (IC) at less cost and using easier-to-manufacture methods. The new Sandia films enable single-mask level sub 5-Volt write antifuses that are compatible with leading-edge IC specifications. Read more

Undergrads Build Hybrid Race Car

by A. J. Fox The Dartmouth, 5 May 2006 A team of students at the Thayer School of Engineering hosted Formula Hybrid, the first collegiate car race to use only hybrid and electric vehicles, at the New Hampshire International Speedway. The event was accompanied by a conference held Wednesday on the development of hybrid cars. Read more

GaAsing Up Cellphones

by Harry Goldstein IEEE Spectrum Online, 1 May 2006 A group of researchers at Freescale Semiconductor Inc., in Austin, Texas, led by Matthias Passlack, have fabricated metal oxide semiconductor field-effect transistors, the types that drive just about every silicon integrated circuit, using gallium arsenide and a novel gate dielectric. Read more

Debate Rages over 450-mm Wafer Fabs

by Mark LaPedus EE Times, 28 Apr 2006 While a heated debate continues to ensue over next-generation, 450-mm wafer fabs, several semiconductor equipment and materials vendors are quietly exploring and developing their first prototype 450-mm technologies. Read more

Bringing Tunability to Ultrafast Nanoplasmonics

by Maaza Malik & Aboubakar Chedikh Beye SPIE Newsroom, accessed 17 May 2006 The nanosciences are stimulating the possibility of engineering novel nanophotonics with tunable, tailored properties. In particular, nanocomposites with metallic nanoparticles embedded in an insulating host matrix, represent a distinctive class of nanoplasmonics: they have specific nonlinear characteristics due to enhancement of the local field. The cost effectiveness of these materials could open up photonic applications in wave mixing, heterodyning, and modulation, and could expand their role in laser applications. Read more

A Chip That Creates Microscale Vortices in Water and Mimics Biochemistry

by Magnus Willander et al. SPIE Newsroom, accessed 17 May 2006 An electrolyte transistor -- essentially a chemical device that controls the flow of electricity -- could help scientists understand and explore the chemical activity between small numbers of molecules. The device could be used in demanding areas such as the sensing of substances from the human body, applications where basic and applied scientists need smart, sensitive, and selective devices that operate in real time. In wet chemistry, for instance, our electrolyte transistor allows micro- and nanoscale observations of reactants forming products. In addition, the platform described here can control dynamic conditions, stirring aqueous reactants by creating microscale vortices for example. Read more

Automated Inspection Applications for Smart Robot Cameras

by Ernie Hall & Xiaoqun Liao SPIE Newsroom, accessed 17 May 2006 An intelligent robot camera using so-called ‘creative control’ can solve a set of problems in dynamic programming and optimal control. Read more

Dropping Cost of Flash Memory Makes Solid-State Data Storage Affordable for More Designers

by John Keller Military & Aerospace Electronics, April 2006 Solid-state data storage, which keeps electronic data in memory chips rather than on spinning magnetic or optical media, has several advantages over its magnetic and optical cousins. Solid-state storage is fast, quiet, and rugged. Until recently however, it was a lot more expensive. That is changing, however, with the advent of relatively inexpensive Flash memory that in large volumes is going into popular commercial electronic devices such as digital cameras and portable MP3 players. Read more

Self-Similar Relaxation Dynamics of a Fluid Wedge in a Hele-Shaw Cell

by Omri Gat et al. arXiv.org E-print Archive, 13 May 2006 Let the interface between two immiscible fluids in a Hele-Shaw cell have, at t=0, a wedge shape. As a wedge is scale-free, the fluid relaxation dynamics are self-similar. We find the dynamic exponent of this self-similar flow and show that the interface shape is given by the solution of an unusual inverse problem of potential theory. We solve this inverse problem analytically for an almost flat wedge, and numerically otherwise. The wedge solution is useful for analysis of pinch-off singularities. Read more

Thin Film Dynamics on a Vertically Rotating Disk Partially Immersed in a Liquid Bath

by K. Afanasiev et al. arXiv.Eprint Archive, 14 MAy 2006 The axisymmetric flow of a thin liquid film is considered for the problem of a vertically rotating disk that is partially immersed in a liquid bath. A model for the fully three-dimensional free-boundary problem of the rotating disk, that drags a thin film out of the bath is set up. From this, a dimension-reduced extended lubrication approximation that includes the meniscus region is derived. This problem constitutes a generalization of the classic drag-out and drag-in problem to the case of axisymmetric flow. The resulting nonlinear fourth-order partial differential equation for the film profile is solved numerically using a finite element scheme. For a range of parameters steady states are found and compared to asymptotic solutions. Patterns of the film profile, as a function of immersion depth and angular velocity are discussed. Read more

Alice in a Micro-Factory

by Debashish Chowdhury arXiv.org E-print Archive, 12 May 2006 Imagine an under water factory which is about 10μm long in each direction. The factory is filled with machines, each typically a few tens of nanometers long, which perform specfic tasks and operate in a well coordinated manner. A cell, the structural and functional unit of life, is not very different from this micro-factory. I begin with Alice's guided tour of this micro-factory in her dream during which the guide shows her wide varieties of the nano-machines in this factory. The style of presentation of the first half of this article is inspired by George Gamow's Alice in Wonderland. In the second half, I introduce the methods of studying the materials and mechanisms of the molecular machines through dialogues; the three participants in this discussion are Alice, her elder brother Alex and her father Albert. The style of presentation of the second half of this article, in terms of a dialogue, is adapted from Galileo's Dialogue Concerning the Two Chief World Systems. Albert, a professor of biophysics, emphasizes the crucial differences between the mechanisms of the natural nano-machines and those of their macroscopic counterparts. He also points out some practical applications of this interdisciplinary research in biomedical science and nano-technology. Read more

New Kind of Cement Absorbs Pollution

PhysOrg.com, 16 May 2006 Italcementi, which spent 10 years developing its TX Active, said the building material is capable of reducing urban pollution by more than 40 percent, the Italian news agency ANSA reported Tuesday. Tests on a road near Milan showed TX Active cut the level of nitrogen dioxide and carbon monoxide by as much as 65 percent. It functions via a chemical process called photocatalysis, whereby sunlight triggers a chemical reaction when titanium dioxide on the surface of the cement comes into contact with pollutants in the air. TX Active works most effectively in bright sunlight. Italcementi said test results have been verified by independent bodies like the National Research Council. TX Active cement has already been used on a number of buildings, including Air France's new headquarters at Paris' Charles de Gaulle Airport, Rome's Dives in Misericordia church and Bordeaux's Hotel de Police.

Redirecting Mouth of Mississippi River Proposed as Way to Save Louisiana Coast

PhysOrg.com, 15 May 2006 Vince Neary, Tennessee Tech University associate professor of civil and environmental engineering, says such a bold, large-scale plan is necessary to stop the disappearance of the state's coastal wetlands -- which act as natural speed bumps against hurricanes and storm surges. Read more

Capillarity Induced Solvent-Actuated Bonding of Polymeric Microfluidic Devices

by Jayna J. Shah et al. Analytical Chemistry, 15 May 2006 Rapid, robust, and economical fabrication of fluidic microchannels is of fundamental importance for the successful development of disposable lab-on-a-chip devices. We present a solvent-actuated bonding method for fabricating polymeric microfluidic devices at room temperature. A PMMA sheet with an imprinted microchannel was clamped to a blank PMMA sheet, and then 80 ± 5 L of acetone was introduced at one end of the fluidic channel and aspirated out at the other end. As the solvent moved down the channel, capillary forces drew a fraction of the solvent into the interstitial space between the two polymeric substrates. After aspiration, the assembly was incubated in the clamp for 5 min for effective bond formation. The quantity of the bonding solvent, its water content and flow rate, along with residence time in the channel were found to have significant impact on the bond quality and the channel integrity. Microfluidic electrophoretic separations of a 400-base DNA ladder were performed in devices fabricated using this method in less than 8 min with efficiencies routinely between 2 × 10⁶ and 3 × 10⁶ plates/m. The simplicity and economy of this technique make it amenable for automation and mass production, which could make polymeric substrates more attractive for single-use chemical analysis devices. Read more

'Hybrid' Assembly Technique Connects Optical Devices Precisely

by Matthew Peach optics.org News, 17 May 2006 A novel, field-proven method of aligning optical dvices and assocaited borads has been developed by the Centre for Integrated Photonics (CIP), based in Ipswich, UK. It is claimed to cut both the cost and effort of actively aligning devices and provides a means of creating the sophisticated building-blocks required for integrated optical devices. Read more

Military Plans Tests in Search for an Alternative to Oil-Based Fuel

by Thom Shanker New York Times, 14 May 2006 When an F-16 lights up its afterburners, it consumes nearly 28 gallons of fuel per minute. No wonder, then, that of all the fuel the United States government uses each year, the Air Force accounts for more than half. The Air Force may not be in any danger of suffering inconveniences from scarce or expensive fuel, but it has begun looking for a way to power its jets on something besides conventional fuel. Read more

Patent Office Ponders Peer Scrutiny

by Geoff Brumfiel news@nature.com, 15 May 2006 The scientific community depends on peer review to make sure that papers are tip-top; could it work for inventions too? That's the question being pondered by the US Patent and Trademark Office, as it mulls over a peer-review programme for patent applications. Read more

Mechanical Behaviour of Hybrid SiO2-PMMA Coatings Measured By Nanoindentation

by J.L. Almaral-Sanchez AZojomo, 2 May 2006 Hybrid coatings of silica-polymethylmethacrylate were prepared by a modified sol-gel process using different molar relationships for TEOS:polymethylmethacrylate and constant quantities of 3-methacryloxypropyl-trimethoxysilane as bonding agent, for all the samples. Coatings were deposited on glass substrates by the dip coating method. The hybrid coatings were studied by Fourier transform infrared spectroscopy and by two different depth sensing indentation systems. Infrared spectroscopy measurements clearly showed the formation of the hybrid material. The effective hardness of the coatings was analyzed using the work of indentation model. From the indentation measurements we found that the mechanical properties of the hybrid coatings were improved in comparison with those of conventional acrylics. Hardness of the hybrid coatings was from three times to more than one order of magnitude higher than the acrylic hardness, depending on the molar ratio. An extra hardening phenomenon was measured at the surface of the coatings, which is probably due to an enrichment of silica at this region. Finally we found that hardness of the coatings decreases monotonically with the polymethylmethacrylate content. These results allow us to prepare hybrid coatings with tailored mechanical properties. Read more

Researchers Look to Nature for Design Inspiration

Georgia Institute of Technology Public Release, 15 May 2006 Georgia Tech researchers studying nature's masterful and time-tested design techniques to find answers for some of science's toughest design challenges presented their research May 11 and May 12 at the International Symposium for Biologically-inspired Design and Engineering at Georgia Tech. Read more

An Amplitude Modulator For Digital Communications

by J. A. Davila-Pintle et al. AZojomo, 2 May 2006 By employing chemical bath deposition, polycrystalline thin films of CdS were grown on glass substrates. During the process of growth relative volumes of nitrate of erbium penta-hydrate (Er(NO₃)₃5H₂O) were added in aqueous solution of CdS in order to obtain different levels of doping. The samples obtained by this method were electrically and optically characterized determining the dark conductivity, carrier density, and the photoconductivity in the 590 to 451 nm range respectively. Finally the optimal sample with better electrical and optical characteristics was chosen to build an amplitude modulator for digital communications. Read more

Biorobotics Challenges Engineers

by R. Colin Johnson EE Times, 17 MAy 2006 While enabling better robots, biorobotics are also encouraging engineers to become neuroscientists, an expert told the IEEE's International Conference on Robotics and Automation. "Biorobotics offers a new paradigm for engineers," said keynote speaker Paolo Dario. "The engineer no longer just cooperates with neuroscientists, but has become a scientist too in order to discover basic biological principles that make their job easier." Read more

Efficient Operation of Coded Packet Networks

by Desmond S. Lun arXiv.org E-print Archive, 15 May 2006 A fundamental problem faced in the design of almost all packet networks is that of efficient operation -- of reliably communicating given messages among nodes at minimum cost in resource usage. We present a solution to the efficient operation problem for coded packet networks, i.e., packet networks where the contents of outgoing packets are arbitrary, causal functions of the contents of received packets. Such networks are in contrast to conventional, routed packet networks, where outgoing packets are restricted to being copies of received packets and where reliability is provided by the use of retransmissions. This thesis introduces four considerations to coded packet networks: 1) efficiency, 2) the lack of synchronization in packet networks, 3) the possibility of broadcast links, and 4) packet loss. We take these considerations and give a prescription for operation that is novel and general, yet simple, useful, and extensible. [Ph.D. dissertation, MIT, June 2006] Read more

On the Possible Computational Power of the Human Mind

by Hector Zenil & Francisco Hernandez-Quiroz arXiv.org E-print Archive, 15 May 2006 The aim of this paper is to address the question: Can an artificial neural network model be used as a possible characterization of the power of the human mind? We will discuss what might be the relationship between such a model and its natural counterpart. A possible characterization of the different power capabilities of the mind is suggested in terms of the information contained (in its computational complexity) or achievable by it. Such characterization takes advantage of recent results based on natural neural networks and the computational power of arbitrary artificial neural networks. The possible acceptance of neural networks as the model of the human mind's operation makes the aforementioned quite relevant. Read more

An Internet Framework to Bring Coherence between WAP and HTTP

arXiv.org E-print Archive, 15 May 2006 by Al-Mukaddim Khan Pathan et al. To bring coherence between Wireless Access Protocol (WAP) and Hyper Text Transfer Protocol (HTTP), in this paper, we have proposed an enhanced Internet framework, which incorporates a new markup language and a browser compatible with both of the access control protocols. This Markup Language and the browser enables co-existence of both Hyper Text Markup Language (HTML) and Wireless Markup Language (WML) contents in a single source file, whereas the browser incorporates the ability to hold contents compliant with both HTTP and WAP. The proposed framework also bridges the security gap that is present in the existing mobile Internet framework. Read more

A Case for Cooperative and Incentive-Based Coupling of Distributed Clusters

bt Rajiv Ranjan at al. arXiv.org E-print Archive, 15 May 2006 Research interest in Grid computing has grown significantly over the past five years. Management of distributed resources is one of the key issues in Grid computing. Central to management of resources is the effectiveness of resource allocation as it determines the overall utility of the system. The current approaches to superscheduling in a grid environment are non-coordinated since application level schedulers or brokers make scheduling decisions independently of the others in the system. Clearly, this can exacerbate the load sharing and utilization problems of distributed resources due to suboptimal schedules that are likely to occur. To overcome these limitations, we propose a mechanism for coordinated sharing of distributed clusters based on computational economy. The resulting environment, called Grid-Federation, allows the transparent use of resources from the federation when local resources are insufficient to meet its users' requirements. The use of computational economy methodology in coordinating resource allocation not only facilitates the QoS based scheduling, but also enhances utility delivered by resources. Read more

SLA-Based Coordinated Superscheduling Scheme and Performance for Computational Grids

by Rajiv Ranjan et al. arXiv.org E-print Archive, 15 May 2006 The Service Level Agreement (SLA) based grid superscheduling approach promotes coordinated resource sharing. Superscheduling is facilitated between administratively and topologically distributed grid sites by grid schedulers such as Resource brokers. In this work, we present a market-based SLA coordination mechanism. We based our SLA model on a well-known contract net protocol. The key advantages of our approach are that it allows: (i) resource owners to have finer degree of control over the resource allocation that was previously not possible through traditional mechanism and (ii) superschedulers to bid for SLA contracts in the contract net with focus on completing the job within the user specified deadline. In this work, we use simulation to show the effectiveness of our proposed approach. Read more

Utility Computing and Global Grids

by Chee Shin Yeo et al. arXiv.org E-print Archive, 12 May 2006 This report focuses on the use of Grid technologies to achieve utility computing. An overview of how Grids can support utility computing is first presented through the architecture of Utility Grids. Then, utility-based resource allocation is described in detail at each level of the architecture. Finally, some industrial solutions for utility computing are discussed. Read more

Optimal Distributed Power Control, Routing, and Congestion Control in Wireless Networks

by Yufang Xi & Edmund M. Yeh arXiv.org E-print Archive, 11 May 2006 We present a unified analytical framework within which power control, rate allocation, routing, and congestion control for wireless networks can be optimized in a coherent and integrated manner. We consider a multi-commodity flow model with a CDMA-based physical-layer scheme in which power control and routing variables are chosen to minimize convex link costs reflecting, for instance, average queueing delay. Distributed network algorithms where joint power control and routing are performed on a node-by-node basis are presented. We show that with appropriately chosen parameters, these algorithms iteratively converge to the global optimum from any initial point with finite cost. We then extend the results to wireless networks with more general coding/modulation schemes where the physical-layer achievable rate region is given by an arbitrary convex set, and the link costs are quasi-convex. Finally, we demonstrate that congestion control can be seamlessly incorporated into our framework, so that algorithms developed for power control and routing can naturally be extended to optimize user input rates. Read more

Towards Organization of Molecular Machines at Interfaces

by M. Clemente-León et al. Advanced Materials, May 2006 A team of chemists from France, Italy, Spain, the UK, and the US are working together to bridge the gap between nanoscience and nanotechnology. They have now devised a method that could allow them to organize tiny molecular machines on a surface and so build devices that pack in thousands of times as many switching units, for instance, than is possible with a conventional silicon chip. Read more

100-to-1 Bandwidth

PhysOrg.com, 10 May 2006 By taking advantage of a phenomenon that earlier designers had struggled to avoid, engineers at the Georgia Tech Research Institute have developed a new approach to phased-array antenna design that could allow a single ultra-wideband device to do the job of five conventional antennas. Read more

Strained Silicon as a New Electro-Optic Material

by Rune S. Jacobsen et al. Nature, 11 May 2006 For decades, silicon has been the material of choice for mass fabrication of electronics. This is in contrast to photonics, where passive optical components in silicon have only recently been realized. The slow progress within silicon optoelectronics, where electronic and optical functionalities can be integrated into monolithic components based on the versatile silicon platform, is due to the limited active optical properties of silicon. Recently, however, a continuous-wave Raman silicon laser was demonstrated; if an effective modulator could also be realized in silicon, data processing and transmission could potentially be performed by all-silicon electronic and optical components. Here we have discovered that a significant linear electro-optic effect is induced in silicon by breaking the crystal symmetry. The symmetry is broken by depositing a straining layer on top of a silicon waveguide, and the induced nonlinear coefficient, X⁽²⁾ ~15 pm V^-1, makes it possible to realize a silicon electro-optic modulator. The strain-induced linear electro-optic effect may be used to remove a bottleneck in modern computers by replacing the electronic bus with a much faster optical alternative. Read more

Firm Claims Bulk Aluminum Nitride Breakthrough

by Dylan McGrath EE Times, 11 May 2006 Claiming to leverage nanotechnology to grow crystals that wouldn’t occur naturally on earth, bulk aluminum nitride supplier Crystal IS said it has developed a manufacturing technique to grow a novel crystal which, when sliced and polished, can be used as a semiconductor substrate for the next generation in optoelectronic and high-power RF devices. Read more

Power Up with Magnetic Bacteria

by Stephen Leahy Wired News, 12 May 2006 A 16-year-old high school student has invented a new way of producing electricity by harnessing the brawny power of bacteria. Kartik Madiraju, an 11th-grader from Montreal, was able to generate about half the voltage of a normal AA battery with a fifth of an ounce of naturally occurring magnetic bacteria. And the bacteria kept pumping current for 48 hours nonstop. Read more

USC Engineering Class Creates Tools to Analyze Musical Expression

University of Southern California Public release, 11 May 2006 Music expresses and elicits emotion. But how, exactly? Philosophers have been fascinated by the question since Pythagoras. At the USC Viterbi School of Engineering, Elaine Chew, assistant professor of industrial and systems engineering, now teaches a graduate course on using computational and other engineering tools to look for answers. Read more

Carbon Nanotube Sheets as Electrodes in Organic Light-Emitting Diodes

by C. M. Aguirre et al. Applied Physics Letters, 1 May 2006 High performance organic light-emitting diodes (OLEDs) were implemented on transparent and conductive single-wall carbon nanotube sheets. At the maximum achieved brightness of 2800 cd m^–2 the luminance efficiency of our carbon nanotube-based OLED is 1.4 cd A^–1 which is comparable to the 1.9 cd A^–1 measured for an optimized indium tin oxide anode device made under the same experimental conditions. A thin parylene buffer layer between the carbon nanotube anode and the hole transport layer is required in order to readily achieve the measured performance Read more

Evaluation of Grain Orientation in Textured b-Si3N4 Ceramics with High Thermal Conductivity by Electron Microscopy

by Hiromi Nakano, Hiroshi Nakano, & Koji Watari AZojomo, 2 May 2006 b-Si₃N4 ceramics with highly oriented grains shows high thermal conductivity along the tape-casting direction. In order to clearly understand the relationship between microstructure and thermal conductivity in ceramics, we determined the degrees of orientation for each grain and the grain boundary. This work focuses on highly oriented b-Si₃N4 ceramics obtained by tape-casting with seed particles, followed by hot-pressing and HIPing. The degree of grain orientation was determined by an electron diffraction method combined with an electron back-scattered diffraction method. Each grain was oriented within 20 degrees tilting angle from the [0001] axis in the TEM observed specimen. Furthermore, the relationship between the microstructural data and thermal data were compared and discussed for various types of Si₃N4 ceramics. In this case, the appearance of high anisotropic thermal conductivity was caused by crystallographic nature, grain features, and grain purity during a liquid-sintering process. Read more

From Supercomputing to the TeraGrid

The NSF Fact Sheet "From Supercomputing to the TeraGrid" is a timeline of the National Science Foundation's investment in the nation's computational infrastructure begun in the 1960s. View the fact sheet

Merging Telecommunication Backbone Networks with IP Optical Technologies

by Shigeo Urushidani & Ichiro Inoue SPIE News room, accessed 12 May 2006 The rapid growth in broadband Internet-related services is expected to reach roughly half of all households in Japan by 2010. The maximum speed has rapidly grown from a few kbits/s to hundreds of Mbits/s. In parallel, we have been seeing various new services emerging, including voice over IP, multimedia file downloads, and videoconferencing. All of these new services are based on IP, and, since optical technology offers exceptional capacity, we see this as the most promising infrastructure with which to support them. What is needed is a way to integrate and migrate IP and optical technologies into the single backbone network architecture. Read more

Self-Managing Intelligent Optical Networks for Smarter, Tougher, and Cheaper Systems

by Alan Willner SPIE Newsroom, accessed 12 May 2006 When envisioning the 10-year horizon of optical networks, there are certain laudable goals that may be pursued, such as higher capacity, throughput, stability, reconfigurability, flexibility, and security. These network goals come with a rich set of technical challenges. Read more

Optical Communications Work Best over Relatively Short Distances in Space

by Morio Toyoshima et al. SPIE Newsroom, accessed 12 May 2006 Optical communication systems have advantages over RF systems that include a wider bandwidth, larger capacity, lower power consumption, more compact equipment, greater security against eavesdropping, and immunity from interference. Because of this they are expected to revolutionize space system architectures. Read more

IMS and the Next Generation of Mobile Networks

by Naser Partovi & Amnon Ptashek SPIE Newsroom, accessed 12 May 2006 Most cellular networks are based on 2G or 2.5G technology. However, carriers around the world are upgrading to third generation wideband code-division multiple access and universal mobile telecommunications system to support multimedia services such as music and video downloads. To this end they are keeping close watch on a new addition to 3G technology: the IP multimedia subsystem. Read more

Molecular Sorting by Electrical Steering of Microtubules in Kinesin-Coated Channels

by Martin G. L. van den Heuvel, Martijn P. de Graaff, & Cees Dekker Science, 12 May 2006 Integration of biomolecular motors in nanoengineered structures raises the intriguing possibility of manipulating materials on nanometer scales. We have managed to integrate kinesin motor proteins in closed submicron channels and to realize active electrical control of the direction of individual kinesin-propelled microtubule filaments at Y junctions. Using this technique, we demonstrate molecular sorting of differently labeled microtubules. We attribute the steering of microtubules to electric field–induced bending of the leading tip. From measurements of the orientation-dependent electrophoretic motion of individual, freely suspended microtubules, we estimate the net applied force on the tip to be in the picoNewton range and we infer an effective charge of 12 e– per tubulin dimer under physiological conditions. Raed more

Observation of Backward Pulse Propagation Through a Medium with a Negative Group Velocity

by George M. Gehring et al. Science, 12 May 2006 The nature of pulse propagation through a material with a negative value of the group velocity has been mysterious, as simple models seem to predict that pulses will propagate "backward" through such a material. Using an erbium-doped optical fiber and measuring the time evolution of the pulse intensity at many points within the fiber, we demonstrate that the peak of the pulse does propagate backward inside the fiber, even though the energy flow is always in the forward direction. Read more

Simultaneous Negative Phase and Group Velocity of Light in a Metamaterial

by Gunnar Dolling et al. Science, 12 May 2006 We investigated the propagation of femtosecond laser pulses through a metamaterial that has a negative index of refraction for wavelengths around 1.5 micrometers. From the interference fringes of a Michelson interferometer with and without the sample, we directly inferred the phase time delay. From the pulse-envelope shift, we determined the group time delay. In a spectral region, phase and group velocity are negative simultaneously. This means that both the carrier wave and the pulse envelope peak of the output pulse appear at the rear side of the sample before their input pulse counterparts have entered the front side of the sample. Read more

Formation and Subdivision of Deformation Structures During Plastic Deformation

by Bo Jakobsen et al. Science, 12 May 2006 During plastic deformation of metals and alloys, dislocations arrange in ordered patterns. How and when these self-organization processes take place have remained elusive, because in situ observations have not been feasible. We present an x-ray diffraction method that provided data on the dynamics of individual, deeply embedded dislocation structures. During tensile deformation of pure copper, dislocation-free regions were identified. They showed an unexpected intermittent dynamics, for example, appearing and disappearing with proceeding deformation and even displaying transient splitting behavior. Insight into these processes is relevant for an understanding of the strength and work-hardening of deformed materials. Read more

Scale-Free Network Growth by Ranking

by Santo Fortunato, Alessandro Flammini , & Filippo Menczer arXiv.org E-print Archive, 9 May 2006 Network growth is currently explained through mechanisms that rely on node prestige measures, such as degree or fitness. In many real networks those who create and connect nodes do not know the prestige values of existing nodes, but only their ranking by prestige. We propose a criterion of network growth that explicitly relies on the ranking of the nodes according to any prestige measure, be it topological or not. The resulting network has a scale-free degree distribution when the probability to link a target node is any power law function of its rank, even when one has only partial information of node ranks. Our criterion may explain the frequency and robustness of scale-free degree distributions in real networks, as illustrated by the special case of the Web graph. Read more

New Supercomputing Center to Advance the Science of Nanotechnology

Rensselaer Polytechnic Institute Public Release, 10 May 2006 Rensselaer Polytechnic Institute, in collaboration with IBM and New York state, has announced a $100-million partnership to create the world's most powerful university-based supercomputing center, and a top 10 supercomputing center of any kind in the world. Read more

DoD Funding Opportunity - Large Tactical Sensor Networks

The goal of the Large Tactical Sensor Networks program is to develop and demonstrate measurable advances to enable sensor networks of unmanned vehicles and unattended ground sensors to rapidly respond to small unit intelligence requirements, automatically sense the tactical environment and perform automated translation, fusion, and dissemination of sensor data into actionable intelligence. The Office of Naval Research seeks both to automate processes that provide small tactical units with an automated understanding of relationships among battlespace objects and events and to automate management of multiple hypotheses about the intent of these objects and groupings. Data analysis and fusion algorithms resulting from this research will be integrated into emerging net-centric Navy and Marine Corps Command & Control and Intelligence, Surveillance, and Reconnaissance acquisition programs and Distributed Common Ground System through a Service Oriented Architecture. Sensor network management and human interface technologies will also be designed to be integrated with relevant naval unmanned vehicle systems such as the Marine Corps Vertical Unmanned Air Vehicle (UAV), Gladiator, and Tier II UAV. Read more

Shape-Shifting Car Will Brace for Impact

by Tom Simonite NewScientist.com, 10 May 2006 A car that can anticipate a side-on impact and subtly alter its body shape to absorb the force of the crash is being developed by researchers in Germany. Read more

A Mesoscopic Approach for Multi-Phase Flows in Nano-Corrugated Channels

by R. Benzi et al. arXiv.org E-print Archive, 4 May 2006 An approach based on a lattice version of the Boltzmann kinetic equation for describing multi-phase flows in nano- and micro-corrugated devices is proposed. We specialize it to describe the wetting/dewetting transition of fluids in presence of nanoscopic grooves etched on the boundaries. This approach permits to retain the essential supra-molecular details of fluid-solid interactions without surrendering -- actually boosting -- the computational efficiency of continuum methods. The mesoscopic method is first validated quantitatively against Molecular Dynamics (MD) results of Cottin-Bizonne et al. and then applied to more complex situations which are hardly accessible to MD simulations. The resulting analysis confirms that surface roughness and capillary effects may conspire to promote a counter-intuitive but significant reduction of the flow drag with substantial enhancement in the mass flow rates and slip-lengths in the micrometric range for highly hydrophobic surfaces. Read more

Non-Newtonian Thin Films with Normal Stresses: Dynamics and Spreading

by Arezki Boudaoud arXiv.org E-print Archive, 7 May 2006 The dynamics of thin films on a horizontal solid substrate is investigated in the case of non-Newtonian fluids exhibiting normal stress differences, the rheology of which is strongly non-linear. Two coupled equations of evolution for the thickness of the film and the shear rate are proposed within the lubrication approximation. This framework is applied to the motion of an advancing contact line. The apparent dynamic contact angle is found to depend logarithmically on a lengthscale determined solely by the rheological properties of the fluid and the velocity of the contact line. Read more

Patterned Superhydrophobic Surfaces: Toward a Synthetic Mimic of the Namib Desert Beetle

by Lei Zhai et al. Nano Letters, 2 May 2006 (web release) The present study demonstrates a surface structure that mimics the water harvesting wing surface of the Namib Desert beetle. Hydrophilic patterns on superhydrophobic surfaces were created with water/2-propanol solutions of a polyelectrolyte to produce surfaces with extreme hydrophobic contrast. Selective deposition of multilayer films onto the hydrophilic patterns introduces different properties to the area including superhydrophilicity. Potential applications of such surfaces include water harvesting surfaces, controlled drug release coatings, open-air microchannel devices, and lab-on-chip devices. Read more

12-Qubits Reached in Quantum Information Quest

Perimeter Institute for Theoretical Physics Public Release, 8 May 2006 In the drive to understand and harness quantum effects as they relate to information processing, scientists in Waterloo and Massachusetts have benchmarked quantum control methods on a 12-Qubit system. Their research was performed on the largest quantum information processor to date. Read more

New 'Metal Sandwich' May Break Superconductor Record

Duke University Public Release, 8 May 2006 After an exhaustive data search for new compounds, researchers at Duke University's Pratt School of Engineering have discovered a theoretical "metal sandwich" that is expected to be a good superconductor. Superconductive materials have no resistance to the flow of electric current. Read more

Nanotube Sandwiches Could Lead to Better Composite Materials

Rensselaer Polytechnic Institute Public Release, 8 May 2006 By stacking layers of ceramic cloth with interlocking nanotubes in between, a team of researchers has created new composites with significantly improved properties compared to traditional materials. The "nanotube sandwiches" could find use in a wide array of structural applications. Read more

Peer to Peer Networks for Defense Against Internet Worms

by Srinivas Shakkottai & R. Srikant arXiv.org E-print Archive, 8 May 2006 Internet worms, which spread in computer networks without human mediation, pose a severe threat to computer systems today. The rate of propagation of worms has been measured to be extremely high and they can infect a large fraction of their potential hosts in a short time. We study two different methods of patch dissemination to combat the spread of worms. We first show that using a fixed number of patch servers performs woefully inadequately against Internet worms. We then show that by exploiting the exponential data dissemination capability of P2P systems, the spread of worms can be halted very effectively. We compare the two methods by using fluid models to compute two quantities of interest: the time taken to effectively combat the progress of the worm and the maximum number of infected hosts. We validate our models using Internet measurements and simulations. Read more

A Formal Measure of Machine Intelligence

by Shane Legg & Marcus Hutter arXiv.org E-print Archive, 6 May 2006 A fundamental problem in artificial intelligence is that nobody really knows what intelligence is. The problem is especially acute when we need to consider artificial systems which are significantly different to humans. In this paper we approach this problem in the following way: We take a number of well known informal definitions of human intelligence that have been given by experts, and extract their essential features. These are then mathematically formalised to produce a general measure of intelligence for arbitrary machines. We believe that this measure formally captures the concept of machine intelligence in the broadest reasonable sense. Read more

Transponder Extends the Reach at 10 Gbit/s

by Tami Freeman Fibers.org News, 9 May 2006 Dispersion tolerance is a critical factor for high-data-rate optical networks: the less dispersion a link can cope with, the more compensation it will need -- and this can be costly. With standard 10 Gbit/s transponders offering a reach of around 80 km, a typical metro link of 300-350 km will require several external dispersion-compensating modules -- commonly based on lengths of dispersion-compensating fibre -- to maintain signal integrity along its length. Read more

Brain Power

by Rahul Sarpeshkar IEEE Spectrum Online, May 2006 A team of researchers at the Massachusetts Institute of Technology have finished work on a tiny bionic ear processor that can be powered by a 2-gram battery that requires a wireless recharge every two weeks. The development signals the beginning of making low-power circuits that have the ability to restore hearing in deaf people, according to the lead researcher, an associate professor of electrical engineering at MIT. The researchers used a microphone and preamplifier to transform sound into an analog signal transmitted to the listener through an automatic gain-control circuit, which lessens the range of intensity. Then, a 16-channel spectrum analyzer distributes the signal into frequency components, delaying digitization until the signal has been computed by the circuit. This allows for the intensity of the current to be controlled, leaving more power for stimulating the nerves. Read more

Scientists Develop Simple Alternative for Harvesting Daylight and Saving Energy

Rensselaer Polytechnic Institute Press Release, 19 Apr 2006 Scientists at Rensselaer Polytechnic Institute’s Lighting Research Center have developed a simple, cost-effective, energy-saving device designed to harvest daylight automatically. The DaySwitch was designed as an alternative to traditional dimming ballast systems that adjust light levels by reducing the lamp current. Read more

Call for Papers - IEEE Conference on Electrical and Hybrid Vehicles

The conference will provide platform for the manufacturers, research workers and academicians to discuss various issues related to electric and hybrid electric vehicles. It will consist of presentations by experts on the state of the art, invited papers on specific issues, observations and findings of research workers, experiences of manufacturers and views of the users. Papers are invited on the following topics or on any other topics relevant to the theme of the conference:

• Electric Vehicles
• Hybrid Electric Vehicles
• Mechanical Design of Electric and Hybrid Electric Vehicles
• Testing and Evaluation of Electric and Hybrid Electric Vehicles
• Electric and Hybrid Electric Vehicle Technology as an Alternative to Conventional Automobile Technology

Read more

Modeling the Optical Properties of Nanoparticles

by Gunnar A. Niklasson SPIE Newsroom, accessed 10 May 2006 The optical properties of nanoparticles are important for both traditional and emerging technologies. Nanoparticles have long been used as coloring agents in glass and paints. Research on nanoparticle optics soared in the 1970s, due to the increased societal interest in solar-energy applications. Today, metallic nanoparticles are used in commercial coatings that absorb at particular solar wavelengths. Recently, the optical absorption of noble metal nanoparticles has been employed as the basis for novel sensors: the enhanced local fields close to particle surfaces makes it possible to detect single molecules by surface-enhanced spectroscopy. Read more

A New Way to Beat the Limits on Shrinking Transistors?

by Adrian Cho Science, 5 May 2006 A new lithography scheme could sidestep a fundamental limit of classical optics and open the way to drawing ultraprecise patterns with simple lasers, a team of electrical engineers and physicists predicts. If it works, the scheme would allow chipmakers to continue to shrink the transistors on microchips using standard technologies. Read more

Environmental Monitoring by Wireless Communication Networks

by Hagit Messer, Artem Zinevich, & Pinhas Alpert Science, 5 May 2006 The global spread of wireless networks brings a great opportunity for their use in environmental studies. Weather, atmospheric conditions, and constituents cause propagation impairments on radio links. As such, while providing communication facilities, existing wireless communication systems can be used as a widely distributed, high-resolution atmospheric observation network, operating in real time with minimum supervision and without additional cost. Here we demonstrate how measurements of the received signal level, which are made in a cellular network, provide reliable measurements for surface rainfall. We compare the estimated rainfall intensity with radar and rain gauge measurements. Read more

Robotic Tentacles Get to Grips with Tricky Objects

by David Hambling NewScientist.com, 8 May 2006 Robotic "tentacles" that can grasp and grapple with a wide variety of objects have been developed by US researchers. The tentacle-like manipulators, known as "Octarms", resemble an octopus's limb or an elephant's trunk. They were developed through a project called OCTOR (sOft robotiC manipulaTORs), which involves several U.S. universities and is funded by the Defense Advanced Research Projects Agency. Read more

Nanotubes Used to Send Signals to Nerve Cells

University of Texas Medical Branch at Galveston Public Release, 8 May 2006 Texas scientists have added one more trick to the amazing repertoire of carbon nanotubes -- the ability to carry electrical signals to nerve cells. Read more

NASA Launches Lunar Lander Contest

by Stefanie Olsen ZDNet News, 5 May 2006 NASA is calling on private industry to build next-generation spacecraft that can land on the moon, and it's got $2 million to back up the bid. On Friday, the U.S. space agency announced it has forged a partnership with the X Prize Foundation, an organization that promotes space exploration, to hold the Lunar Lander Analog Challenge. The contest, for development of a vehicle to simulate a landing on the moon, carries $2.5 million in prizes, including NASA's purse. The X Prize Foundation will host and pay for the competition to take place in Las Cruces, N.M., in October, when it puts on its own X Prize Cup. Read more

Old Solar Tech Back in Limelight

by Martin LaMonica ZDNet News, 5 May 2006 A handful of solar companies are focusing on a venerable technique to harvest more sunlight. The high price of silicon -- the most common material used in solar panels -- is prompting engineers to design solar concentrators, devices that squeeze more electricity out of a slice of silicon or other photovoltaic cells. Read more

DARPA Issues Call for Street-Legal Robot Racers

by Jonathan Skillings ZDNet News, 2 May 2006 The DARPA Grand Challenge has conquered the desert. Now it's ready to move downtown. The Defense Advanced Research Projects Agency plans to hold its third contest for robotic vehicles in November 2007, with a first prize set at $2 million. This would be the agency's first attempt at getting driverless vehicles to negotiate city streets. Read more

Phase and Amplitude Responses of Narrow-Band Optical Filter Measured by Microwave Network Analyzer

by Hsi-Cheng Wang & Keang-Po Ho arXiv.org E-Print Archive, 4 May 2006 The phase and amplitude responses of a narrow-band optical filter are measured simultaneously using a microwave network analyzer. The measurement is based on an interferometric arrangement to split light into two paths and then combine them. In one of the two paths, a Mach-Zehnder modulator generates two tones without carrier and the narrow-band optical filter just passes through one of the tones. The temperature and environmental variations are removed by separated phase and amplitude averaging. The amplitude and phase responses of the optical filter are measured to the resolution and accuracy of the network analyzer. Read more