Scientists and Engineers Apply Nature's Design to Human Problems

Georgia Institute of Technology Press Release, 28 Oct 2005 Copying the ideas of others is usually frowned upon, but when it comes to the work of Mother Nature, scientists are finding they can use nature as a template. An interdisciplinary group of scientists and engineers at the Georgia Institute of Technology recently formed the Center for Biologically Inspired Design with the goal of capitalizing on the rich source of design solutions present in biological processes. The researchers believe nature can inspire design and engineering solutions that are efficient, practical and sustainable and thus have the potential to greatly enhance new technologies, materials and processes. Read more

Road Map for the Controlled Synthesis of CdSe Nanowires, Nanobelts, and Nanosaws - A Step Towards Nanomanufacturing

by C. Ma & Z.L. Wang Advanced Materials, 29 Sep 2005 (online) Researchers have taken an important step toward high-volume production of new nanometer-scale structures with the first systematic study of growth conditions that affect production of one-dimensional nanostructures from the optoelectronic material cadmium selenide. Using the results from more than 150 different experiments in which temperature and pressure conditions were systematically varied, nanotechnology researchers at the Georgia Institute of Technology created a "road map" to guide future nanomanufacturing using the vapor-liquid-solid technique. Read more

Virginia Tech Football Player Uses Prototype Cast

Virginia Tech Press Release, 31 Oct 2005 Virginia Tech's starting running back Cedric Humes was able to play against Boston College despite a broken arm (the ulna bone) thanks, in part, to a prototype composite brace designed for him by Virginia Tech engineers. Read more

Supercomputer Doubles Own Record

BBC News, 28 Oct 2005 The Blue Gene/L supercomputer has broken its own record to achieve more than double the number of calculations it can do a second. It reached 280.6 teraflops -- that is 280.6 trillion calculations a second. The IBM machine, at the US Lawrence Livermore National Laboratory, officially became the most powerful computer on the planet in June. Read more

Observation of Spin Coulomb Drag in a Two-Dimensional Electron Gas

by C. P. Weber et al. Nature, 27 Oct 2005 An electron propagating through a solid carries spin angular momentum in addition to its mass and charge. Of late there has been considerable interest in developing electronic devices based on the transport of spin that offer potential advantages in dissipation, size and speed over charge-based devices. However, these advantages bring with them additional complexity. Because each electron carries a single, fixed value (- e) of charge, the electrical current carried by a gas of electrons is simply proportional to its total momentum. A fundamental consequence is that the charge current is not affected by interactions that conserve total momentum, notably collisions among the electrons themselves. In contrast, the electron's spin along a given spatial direction can take on two values, so that the spin current and momentum need not be proportional. Although the transport of spin polarization is not protected by momentum conservation, it has been widely assumed that, like the charge current, spin current is unaffected by electron-electron (e-e) interactions. Here we demonstrate experimentally not only that this assumption is invalid, but also that over a broad range of temperature and electron density, the flow of spin polarization in a two-dimensional gas of electrons is controlled by the rate of e-e collisions. Read more

Changing Face of the Chameleon

by A. Lindsay Greer & Neil Mathur Nature, 27 Oct 2005 The chalcogens -- the elements in group VI of the periodic table, particularly sulphur (S), selenium (Se) and tellurium (Te) -- react with more electropositive elements, such as silver, to form chalcogenides. These are chameleon compounds: they can be crystalline or amorphous, metallic or semiconducting, and conductors of ions or electrons. Already important in optical storage discs and fibres, they are now being proposed as the basis for solid-state memory technologies. Two recent conferences have demonstrated that devices using chalcogenides hinge on thermal and dynamic phenomena involving electronic, atomic and ionic processes. The links between these phenomena are not fully established, so unsuspected technological opportunities may well lie in store. Read more

Strong Quantum-Confined Stark Effect in Germanium Quantum-Well Structures on Silicon

by Yu-Hsuan Kuo et al. Nature, 27 Oct 2005 Silicon is the dominant semiconductor for electronics, but there is now a growing need to integrate such components with optoelectronics for telecommunications and computer interconnections. Silicon-based optical modulators have recently been successfully demonstrated; but because the light modulation mechanisms in silicon are relatively weak, long devices or sophisticated high-quality-factor resonators have been necessary. Thin quantum-well structures made from III-V semiconductors such as GaAs, InP and their alloys exhibit the much stronger quantum-confined Stark effect (QCSE) mechanism, which allows modulator structures with only micrometres of optical path length. Such III-V materials are unfortunately difficult to integrate with silicon electronic devices. Germanium is routinely integrated with silicon in electronics, but previous silicon-germanium structures have also not shown strong modulation effects. Here we report the discovery of the QCSE, at room temperature, in thin germanium quantum-well structures grown on silicon. The QCSE here has strengths comparable to that in III-V materials. Its clarity and strength are particularly surprising because germanium is an indirect gap semiconductor; such semiconductors often display much weaker optical effects than direct gap materials. This discovery is very promising for small, high-speed, low-power optical output devices fully compatible with silicon electronics manufacture. Read more

Proceedings of the IEEE Examines Need to Revolutionize Power Industry

On the 40-year anniversary of the blackout of 1965, the November special issue of Proceedings of the IEEE takes a close-up look at the increasing need to transform the electric power industry. The issue examines recurring problems in the industry, such as power shortages, issues surrounding engineering and policies, and error prevention techniques. Papers consider online adoption as a realistic method of changing supply demand and patterns, as well as design and operational challenges to reliable electricity services. Read more

Two Brains, One Car - Actively Controlled Steering

by B. Tongue Control Systems Magazine, October 2005 Actively controlled steering (ACS) systems enable vehicle autonomy and facilitate the trend in active stabilization and control that has been developing steadily over the last decade. These systems can improve the overall driving experience. Employing an on-board microprocessor, ACS is both a necessary enabler for fully autonomous vehicular operations and a functional element that can improve a car's operational envelope independent of autonomous operation. In the paper, examples of ACS are given, and BMW's active steering system and stability controllers based on ACS systems are discussed. Read more

A League Of Extraordinary Women

by Prachi Patel-Predd IEEE Spectrum Online, October 2005 All too few girls consider engineering as a career, and the profession is the poorer for it, as talented individuals seek vocations elsewhere. But a new program is in the works in the United States to attract young women to engineering -- and to keep them in the career. Read more

Layered Orthogonal Lattice Detector for Two Transmit Antenna Communications

by Massimiliano Siti & Michael P. Fitz arXiv.org E-print Archive, 22 Oct 2005 A novel detector for multiple-input multiple-output communications is presented. The algorithm belongs to the class of the lattice detectors, i.e. it finds a reduced complexity solution to the problem of finding the closest vector to the received observations. The algorithm achieves optimal maximum-likelihood (ML) performance in case of two transmit antennas, at the same time keeping a complexity much lower than the exhaustive search-based ML detection technique. Also, differently from the state-of-art lattice detector (namely sphere decoder), the proposed algorithm is suitable for a highly parallel hardware architecture and for a reliable bit soft-output information generation, thus making it a promising option for real-time high-data rate transmission. Read more

On-Off Frequency-Shift-Keying for Wideband Fading Channels

by Mustafa Cenk Gursoy, Sergio Verdu, & H. Vincent Poor arXiv.org E-print Archive, 24 Oct 2005 M-ary On-Off Frequency-Shift-Keying (OOFSK) is a digital modulation format in which M-ary FSK signaling is overlaid on On/Off keying. This paper investigates the potential of this modulation format in the context of wideband fading channels. First it is assumed that the receiver uses energy detection for the reception of OOFSK signals. Capacity expressions are obtained for the cases in which the receiver has perfect and imperfect fading side information. Power efficiency is investigated when the transmitter is subject to a peak-to-average power ratio (PAR) limitation or a peak power limitation. It is shown that under a PAR limitation, it is extremely power inefficient to operate in the very low SNR regime. On the other hand, if there is only a peak power limitation, it is demonstrated that power efficiency improves as one operates with smaller SNR and vanishing duty factor. Also studied are the capacity improvements that accrue when the receiver can track phase shifts in the channel or if the received signal has a specular component. To take advantage of those features, the phase of the modulation is also allowed to carry information. Read more

A Simple Cooperative Diversity Method Based on Network Path Selection

by Aggelos Bletsas et al. arXiv.org E-print Archive, 24 Oct 2005 Cooperative diversity has been recently proposed as a way to form virtual antenna arrays that provide dramatic gains in slow fading wireless environments. However most of the proposed solutions require distributed space-time coding algorithms, the careful design of which is left for future investigation if there is more than one cooperative relay. We propose a novel scheme, that alleviates these problems and provides diversity gains on the order of the number of relays in the network. Our scheme first selects the best relay from a set of M available relays and then uses this best relay for cooperation between the source and the destination. We develop and analyze a distributed method to select the best relay that requires no topology information and is based on local measurements of the instantaneous channel conditions. This method also requires no explicit communication among the relays. The success (or failure) to select the best available path depends on the statistics of the wireless channel, and a methodology to evaluate performance for any kind of wireless channel statistics, is provided. Information theoretic analysis of outage probability shows that our scheme achieves the same diversity-multiplexing tradeoff as achieved by more complex protocols, where coordination and distributed space-time coding for M nodes is required. The simplicity of the technique, allows for immediate implementation in existing radio hardware and its adoption could provide for improved flexibility, reliability and efficiency in future 4G wireless systems. Read more

On Coding for Reliable Communication over Packet Networks

by Desmond S. Lun et al. arXiv.org E-print Archive, 23 Oct 2005 We present a capacity-achieving coding scheme for unicast or multicast over lossy packet networks. In the scheme, intermediate nodes perform additional coding yet do not decode nor even wait for a block of packets before sending out coded packets. Rather, whenever they have a transmission opportunity, they send out coded packets formed from random linear combinations of previously received packets. All coding and decoding operations have polynomial complexity. We show that the scheme is capacity-achieving as long as packets received on a link arrive according to a process that has an average rate. Thus, packet losses on a link may exhibit correlation in time or with losses on other links. In the special case of Poisson traffic with i.i.d. losses, we give error exponents that quantify the rate of decay of the probability of error with coding delay. Our analysis of the scheme shows that it is not only capacity-achieving, but that the propagation of packets carrying "innovative" information follows the propagation of jobs through a queueing network, and therefore fluid flow models yield good approximations. We consider networks with both lossy point-to-point and broadcast links, allowing us to model both wireline and wireless packet networks. Read more

Comparing Computational Power

by Udi Boker & Nachum Dershowitz arXiv.org E-print Archive, 23 Oct 2005 It is common practice to compare the computational power of different models of computation. For example, the recursive functions are strictly more powerful than the primitive recursive functions, because the latter are a proper subset of the former (which includes Ackermann's function). Side-by-side with this "containment" method of measuring power, it is standard to use an approach based on "simulation". For example, one says that the (untyped) lambda calculus is as powerful -- computationally speaking -- as the partial recursive functions, because the lambda calculus can simulate all partial recursive functions by encoding the natural numbers as Church numerals. The problem is that unbridled use of these two ways of comparing power allows one to show that some computational models are strictly stronger than themselves! We argue that a better definition is that model A is strictly stronger than B if A can simulate B via some encoding, whereas B cannot simulate A under any encoding. We then show that the recursive functions are strictly stronger in this sense than the primitive recursive. We also prove that the recursive functions, partial recursive functions, and Turing machines are "complete," in the sense that no injective encoding can make them equivalent to any "hypercomputational" model. Read more

Ultra Wideband Impulse Radio Systems with Multiple Pulse Types

by Sinan Gezici et al. arXiv.org E-print Archive, 23 Oct 2005 In an ultra wideband (UWB) impulse radio (IR) system, a number of pulses, each transmitted in an interval called a "frame", is employed to represent one information symbol. Conventionally, a single type of UWB pulse is used in all frames of all users. In this paper, IR systems with multiple types of UWB pulses are considered, where different types of pulses can be used in different frames by different users. Both stored-reference (SR) and transmitted-reference (TR) systems are considered. First, the spectral properties of a multi-pulse IR system with polarity randomization is investigated. It is shown that the average power spectral density is the average of the spectral contents of different pulse shapes. Then, approximate closed-form expressions for the bit error probability of a multi-pulse SR-IR system are derived for RAKE receivers in asynchronous multiuser environments. The effects of both inter-frame interference (IFI) and multiple-access interference (MAI) are analyzed. The theoretical and simulation results indicate that SR-IR systems that are more robust against IFI and MAI than a "conventional" SR-IR system can be designed with multiple types of ultra-wideband pulses. Finally, extensions to multi-pulse TR-IR systems are briefly described. Read more

Starting Your PC in a Flash

by Eric Hellweg TechnilogyReview.com, 21 Oct 2005 Since the early 1990s, Bill Gates has had a consistent lament: the standard PC or notebook takes far too long to boot up. Of course, Gates' company, Microsoft, is one of the main culprits: Windows grows bigger and more complex with every release, meaning there's more operating-system code for computers to load into main memory before they're ready for other tasks. Read more

Making a Soft Cell

by Kevin Bullis TechnologyReview.com, 17 Oct 2005 Plastic solar cells can't yet compete with conventional silicon photovoltaics for efficiently producing large-scale power. But they've become good enough that at least one company, Lowell, MA-based Konarka, has moved past the proof-of-concept phase and is putting them into products. Read more

Scale Invariance in Road Networks

by Vamsi Kalapala, Vishal Sanwalani, Aaron Clauset, & Cristopher Moore arXiv.org E-print Archive, 21 Oct 2005 We study the topological and geographic structure of the national road networks of the United States, England and Denmark. By transforming these networks into their dual representation, where roads are vertices and an edge connects two vertices if the corresponding roads ever intersect, we show that they exhibit both topological and geographic scale invariance. That is, we empirically show that the degree distribution of the dual is well-characterized by a power law with exponent 2.0 < alpha < 2.5, and that journeys, regardless of their length, have a largely identical structure. To explain these properties, we introduce and analyze a simple fractal model of road placement that reproduces the observed structure, and suggests a connection between the scaling exponent alpha and the fractal dimensions governing the placement of roads and intersections. Read more

Nanofabrication to Lead to Quantum Computer

PhysOrg.com, 25 Oct 2005 The team of scientists headed by professor Jeremy Levy at Pitts University has developed nanofabrication tools. The team has an electron beam lithography and nano engineering workstation -- with an electron beam capable of adding and taking away from materials to create incredibly small objects. This according to Prof. Levy could lead to create a quantum computer, and it could break all codes on the Internet. Read more

Windscreen Repels Armour-Piercing Bullets

by Will Knight NewScientist.com, 19 Oct 2005 A transparent material tough enough to withstand armour piercing rounds is being tested by the US Air Force. Aluminium oxynitride, known commercially as ALON, could replace the existing bullet-proof glass on military vehicles, which is heavier and less tough. Read more

Enhancing Semiconductor Device Performance Using Ordered Dopant Arrays

by Takahiro Shinada et al. Nature, 20 Oct 2005 As the size of semiconductor devices continues to shrink, the normally random distribution of the individual dopant atoms within the semiconductor becomes a critical factor in determining device performance -- homogeneity can no longer be assumed. Here we report the fabrication of semiconductor devices in which both the number and position of the dopant atoms are precisely controlled. To achieve this, we make use of a recently developed single-ion implantation technique, which enables us to implant dopant ions one-by-one into a fine semiconductor region until the desired number is reached. Electrical measurements of the resulting transistors reveal that device-to-device fluctuations in the threshold voltage (Vth; the turn-on voltage of the device) are less for those structures with ordered dopant arrays than for those with conventional random doping. We also find that the devices with ordered dopant arrays exhibit a shift in Vth, relative to the undoped semiconductor, that is twice that for a random dopant distribution (- 0.4 V versus -0.2 V); we attribute this to the uniformity of electrostatic potential in the conducting channel region due to the ordered distribution of dopant atoms. Our results therefore serve to highlight the improvements in device performance that can be achieved through atomic-scale control of the doping process. Furthermore, ordered dopant arrays of this type may enhance the prospects for realizing silicon-based solid-state quantum computers. Read more

Cleaner, Crazier Cars on Show in Tokyo

by Will Knight NewScientist.com, 21 Oct 2005 Cleaner, smarter automobiles are the theme for the 2005 Tokyo Motor Show in Japan, although high performance and downright wacky concept vehicles have also been revealed. Many of the designs on display at the show will never be made commercially available. However, the event provides insight into the importance many car manufacturers place on certain nascent technologies. Read more

Space Elevators Stuck on the First Floor

by Maggie McKee NewScientist.com, 24 Oct 2005 A NASA competition designed to lay the groundwork for futuristic space elevators has ended with no one scooping the two $50,000 top prizes. But officials say the contest is just the first step in developing the technologies needed to use robots to lift objects into space on long, thin super-strong tethers. Read more

The VoIP Backlash

by Steven Cherry IEEE Spectrum Online, October 2005 Internet-based telephony saves consumers money by bypassing traditional carriers -- but new software lets the carriers block those pennies-per-minute calls. Read more

Nanocar Takes a Test Drive

by Philip Ball news@nature.com, 21 Oct 2005 The world's smallest toy cars have been set rolling. They measure just 3 by 4 nanometres: a million of them parked bumper to tail would cover the length of a flea. And they are stripped down to the absolute basics: just a chassis and two axles with wheels at either end. But they move. Read more

Superhydrophobic Films from Raspberry-Like Particles

by W. Ming et al. Nano Letters, 1 Oct 2005 (online) We report a robust procedure for preparing superhydrophobic hybrid films on which the advancing contact angle for water is about 165 and the roll-off angle of a 10-L water droplet is 3 ± 1. Dual-size surface roughness, which mimics the surface topology of self-cleaning plant leaves, originates from well-defined silica-based raspberry-like particles that are covalently bonded to an epoxy-based polymer matrix. The roughened surface is chemically modified with a layer of poly(dimethylsiloxane). The robustness and simplicity of this procedure may make widespread applications of so-prepared superhydrophobic films possible. Read more

Optoelectronic Chips Give Hope to All-Optical Memory

by Oliver Graydon fibers.org News, 20 Oct 2005 The development of all-optical buffers that can delay and temporarily store light pulses has been given a boost with the demonstration of three types of semiconductor device that can perform the task. Read more

Magnetic-Field-Induced Assemblies of Cobalt Nanoparticles

by Guangjun Cheng et al. Langmuir, 12 Oct 2005 (online) Under the influence of a 0.05 T magnetic field, 15-nm diameter cobalt nanoparticles covered with surfactants in a colloidal solution assemble into highly constrained linear chains along the direction of the magnetic field. The magnetic-field-induced (MFI) chains become floppy after removal of the field, folding into 3D coiled structures upon gentle agitation. The 3D structures are broken into smaller units with vigorous agitation. The nanoparticles redisperse into the solvent upon ultrasonic agitation. Optical microscopy and transmission electron microscopy are used to characterize the morphologies of the nanoparticle assemblies at various stages of this reversible process. The hysteresis loops and zero-field cooled/field cooled curves reveal the interparticle coupling in the assemblies. MFI assembly provides a powerful tool to manipulate magnetic nanoparticles. Read more

White-Light Emission from Magic-Sized Cadmium Selenide Nanocrystals

by Michael J. Bowers II, James R. McBride, & Sandra J. Rosenthal Journal of the American Chemical Society, 18 Oct 2005 (online) Magic-sized cadmium selenide nanocrystals have been pyrolytically synthesized. These ultra-small nanocrystals exhibit broadband emission that covers most of the visible spectrum while not suffering from self absorption. This behavior is a direct result of the extremely narrow size distribution and unusually large Stokes shift. The intrinsic properties of these ultra-small nanocrystals make them an ideal material for applications in solid state lighting and also the perfect platform to study the molecule-to-nanocrystal transition. Read more

Neurochip Effort's Aim: Demystify Alzheimer's

by Ron Wilson EE Times, 24 Oct 2005 One aim of bioelectronics research into neural systems is to advance our species' understanding of the neurological ailments that beset us. In what promises to be a groundbreaking project, the Interuniversity Microelectronics Center is teaming with Catholic University Leuven and Flanders Interuniversity Institute for Biotechnology to do just that. The first goal is a sophisticated chip that would serve as the electronic and chemical interface to neurons. Next up would be a technology for growing neurons "to order" on the chip. Researchers would stimulate those precisely placed neurons and measure the response. Read more

Cars Sag under Weighty Wiring

by Rick DeMeis EE Times, 24 Oct 2005 The typical electronics content of cars is burgeoning; estimates are that the electronics and software account for 40 percent of a vehicle's value. Design engineers face increasing functionality requirements for such automotive systems as infotainment and multimedia, engine and emissions controls, and safety systems ranging from smart airbags to stability control. For these developers, network bus architectures that reduce discrete, dedicated wiring runs, while facilitating the addition of features, can be a godsend-provided they are implemented wisely. Read more

Bridging Dimensions: Demultiplexing Ultrahigh-Density Nanowire Circuits

by Robert Beckman et al. Science, 21 Oct 2005 A demultiplexer is an electronic circuit designed to separate two or more combined signals. We report on a demultiplexer architecture for bridging from the submicrometer dimensions of lithographic patterning to the nanometer-scale dimensions that can be achieved through nanofabrication methods for the selective addressing of ultrahigh-density nanowire circuits. Order log2(N) large wires are required to address N nanowires, and the demultiplexer architecture is tolerant of low-precision manufacturing. This concept is experimentally demonstrated on submicrometer wires and on an array of 150 silicon nanowires patterned at nanowire widths of 13 nanometers and a pitch of 34 nanometers. Read more

Air-Stable All-Inorganic Nanocrystal Solar Cells Processed from Solution

by Ilan Gur et al. Science, 21 Oct 2005 We introduce an ultrathin donor-acceptor solar cell composed entirely of inorganic nanocrystals spin-cast from solution. These devices are stable in air, and post-fabrication processing allows for power conversion efficiencies approaching 3% in initial tests. This demonstration elucidates a class of photovoltaic devices with potential for stable, low-cost power generation. Read more

Announcing First Wave of E-Journals in A New Publishing Initiative

Petroleum Journals Online is pleased to announce a group of open access electronic journals in a new publishing initiative. This initiative is designed to enable petroleum engineers to rapidly publish peer-reviewed articles online while retaining their copyright. Petroleum Journals Online will provide free access to the articles within these new journals on the principle that 'making research freely available to the public supports a greater global exchange of knowledge and that such access is associated with increased readership and increased citation of an author's work'. Read more

Advances in Wireless Biosensor Technology

Academy of Finland Press Release, 18 Oct 2005 Led by Professor Jukka Lekkala, the Wireless research project is developing miniscule subcutaneous sensors, which can be used to monitor, for example, the function of the heart or prosthetic joints even over long periods of time. The Academy of Finland is funding the project, whose goal is to provide the more accurate prediction of changes in patient condition and, in turn, even save lives. Read more

Deterministic Boundary Recognition and Topology Extraction for Large Sensor Networks

by Alexander Kroeller et al. arXiv.org E-print Archive, 17 Oct 2005 We present a new framework for the crucial challenge of self-organization of a large sensor network. The basic scenario can be described as follows: Given a large swarm of immobile sensor nodes that have been scattered in a polygonal region, such as a street network. Nodes have no knowledge of size or shape of the environment or the position of other nodes. Moreover, they have no way of measuring coordinates, geometric distances to other nodes, or their direction. Their only way of interacting with other nodes is to send or to receive messages from any node that is within communication range. The objective is to develop algorithms and protocols that allow self-organization of the swarm into large-scale structures that reflect the structure of the street network, setting the stage for global routing, tracking and guiding algorithms. Read more

Defining a Comprehensive Threat Model for High Performance Computational Clusters

by Dmitry Mogilevsky, Adam Lee, & William Yurcik arXiv.org E-print Archive, 16 Oct 2005 Over the past decade, high performance computational (HPC) clusters have become mainstream in academic and industrial settings as accessible means of computation. Throughout their proliferation, HPC security has been a secondary concern to performance. It is evident, however, that ensuring HPC security presents different challenges than the ones faced when dealing with traditional networks. To design suitable security measures for high performance computing, it is necessary to first realize the threats faced by such an environment. This task can be accomplished by the means of constructing a comprehensive threat model. To our knowledge, no such threat model exists with regards to Cluster Computing. In this paper, we explore the unique challenges of securing HPCs and propose a threat model based on the classical Confidentiality, Integrity and Availability security principles. Read more

Why We Can Not Surpass Capacity: The Matching Condition

by Cyril Measson, Andrea Montanari, & Rudiger Urbanke arXiv.org E-print Archive, 16 Oct 2005 We show that iterative coding systems can not surpass capacity using only quantities which naturally appear in density evolution. Although the result in itself is trivial, the method which we apply shows that in order to achieve capacity the various components in an iterative coding system have to be perfectly matched. This generalizes the perfect matching condition which was previously known for the case of transmission over the binary erasure channel to the general class of binary-input memoryless output-symmetric channels. Potential applications of this perfect matching condition are the construction of capacity-achieving degree distributions and the determination of the number required iterations as a function of the multiplicative gap to capacity. Read more

A Dynamic Infrastructure for Communication in Dynamically Reconfigurable Devices

by Christophe Bobda et al. arXiv.org E-print Archive, 14 Oct 2005 A new paradigm to support the communication among modules dynamically placed on a reconfigurable device at run-time is presented. Based on the network on chip (NoC) infrastructure, we developed a dynamic communication infrastructure as well as routing methodologies capable to handle routing in a NoC with obstacles created by dynamically placed components. We prove the unrestricted reachability of components and pins, the deadlock-freeness and we finally show the feasibility of our approach by means on real life example applications. Read more

Power Boosts for Future Gadgets

by Jo Twist BBC News, 18 Oct 2005 A recent global survey across 15 countries revealed that the most desired features in a future mobile device was a long-life battery. Two-thirds of mobile and personal digital assistant owners said two days' active battery life was vital. The report said that poor battery life on mobile devices was one of the main reasons people did not play more games, music and video on their devices more often. Read more

Rain, Runoff, Subject of UNH Research Center

by Anne Saunders USA TODAY, 13 Oct 2005 Who ever thought a rain-soaked parking lot could provide so much information? In this season of stormy weather and floods, the University of New Hampshire has been studying the runoff that flows off parking lots, roads and lawns -- the chief source of water pollution in the country. Read more

Extracting the Traffic Flows and the Physical Graphs from Timetables

by Maciej Kurant & Patrick Thiran arXiv.org E-print Archive, 17 Oct 2005 Timetables of mass transportation systems contain an information not only about the traffic flows in the network, but also about the topology of the physical infrastructure of the network. However, this data is not given explicitly; it requires an nontrivial preprocessing to be revealed. We propose an algorithm that extracts the physical structure and the network of traffic flows from timetables. We then apply the algorithm to the timetables of the Swiss railway system, and evaluate our approach. Read more

Aspirated Capacitor Measurements of Air Conductivity and Ion Mobility Spectra

by K.L. Aplin arXiv.org E-print Archive, 17 Oct 2005 Measurements of ions in atmospheric air are used to investigate atmospheric electricity and particulate pollution. Commonly studied ion parameters are (1) air conductivity, related to the total ion number concentration, and (2) the ion mobility spectrum, which varies with atmospheric composition. The physical principles of air ion instrumentation are long-established. A recent development is the computerised aspirated capacitor, which measures ions from (a) the current of charged particles at a sensing electrode, and (b) the rate of charge exchange with an electrode at a known initial potential, relaxing to a lower potential. As the voltage decays, only ions of higher and higher mobility are collected by the central electrode and contribute to the further decay of the voltage. This enables extension of the classical theory to calculate ion mobility spectra by inverting voltage decay time series. In indoor air, ion mobility spectra determined from both the novel voltage decay inversion, and an established voltage switching technique, were compared and shown to be of similar shape. Air conductivities calculated by integration were: 5.3 +- 2.5 fS/m and 2.7 +- 1.1 fS/m respectively, with conductivity determined to be 3 fS/m by direct measurement at a constant voltage. Applications of the new Relaxation Potential Inversion Method include air ion mobility spectrum retrieval from historical data, and computation of ion mobility spectra in planetary atmospheres. Read more

A Dry Electrophysiology Electrode Using CNT Arrays

by Giulio Ruffini et al. arXiv.org E-print Archive, 15 Oct 2005 We describe the concept of a dry electrode sensor for biopotential measurement applications (ENOBIO) designed to eliminate the noise and inconvenience associated to the use of electrolytic gel. ENOBIO uses nanotechnology to remove gel-related noise, as well as maintaining a good contact impedance to minimise interference noise. The contact surface of the electrode will be covered with an array/forest of carbon nanotubes and will also be tested with an Ag/AgCl coating to provide ionic-electronic transduction. The nanotubes are to penetrate the outer layers of the skin, the Stratum Corneum, improving electrical contact. We discuss requirements, skin properties, nanotube penetration and transduction, noise sources, prototype design logic and biocompatibility. Read more

Japanese Ministry Tests Vehicle-to-Vehicle Communication Systems

Tech-On!, 13 Oct 2005 On October 12 Japan's Ministry of Land, Infrastructure and Transport (MLIT) conducted a public road test, at it's winter test track in Hokkaido Prefecture, for the "ASV-3" (Advanced Safety Vehicle), a project led by MLIT to reduce accidents by using a vehicle-to-vehicle communication system. Read more

Behind Artificial Intelligence, a Squadron of Bright Real People

by John Markoff New York Times, 14 Oct 2005 The five robots that successfully navigated a 132-mile course in the Nevada desert last weekend demonstrated the re-emergence of artificial intelligence, a technology field that for decades has overpromised and underdelivered. Read more

Power Companies Enter the High-Speed Internet Market

by Ken Belson New York Times, 17 Oct 2005 The idea has been around for years. In Spain and elsewhere in Europe, utility companies have long offered high-speed Internet service to consumers over their power lines. But American utilities are only now beginning to roll out broadband connections on their grid. Read more

Hot-Drawing of Single and Multiwall Carbon Nanotube Fibers for High Toughness and Alignment

by P. Miaudet et al. Nano Letters, 11 Oct 2005 (online) We report a new hot-drawing process for treating wet-spun composite fibers made of single-and multiwall carbon nanotubes and poly(vinyl alcohol). As shown in previous reports, untreated composite nanotube fibers exhibit a very large strain-to-failure, and their toughness, which is the energy needed to break the fibers, exceeds that of any other known materials. However, untreated composite nanotube fibers absorb a very small amount of energy at low strain and become degraded in humid conditions. In this work, we use hot-drawing treatments, a concept inspired from textile technologies, to improve the properties of nanotube/PVA fibers. This treatment yields a crystallinity increase of the PVA and an unprecedented degree of alignment of the nanotubes. These structural modifications lead to a markedly improved energy absorption at low strain and make the fibers resistant to moisture. Hot-drawn nanotube/PVA fibers hold great potential for a number of applications such as bulletproof vests, protective textiles, helmets, and so forth. Read more

Photodetectors Line Up for 40G Transmission Systems

by Tami Freeman fibers.org News, 17 Oct 2005 Scientists at the University of Texas in the US have fabricated photodetectors designed for 40 Gbit/s optical-transmission systems. The use of multimode-waveguide structures enabled the devices to achieve high responsivity and high bandwidth simultaneously. Read more

Linking Rings through Diamines and Clusters

by Marco Affronte et al. Angewandte Chemie International Edition, 13 Sep 2005 (online) Scientists at The University of Manchester have made a major breakthrough which could pave the way for a new type of high-speed computer. Professor Richard Winpenny, of the School of Chemistry and a team of international researchers, have discovered a new method which could hold the key to creating the first practical quantum computers. If built, quantum computers would be the most powerful computers ever made, with speeds millions of times faster than the average PC for some calculations. These speeds would be valuable in factoring large numbers, and therefore extremely useful for encrypting information. Professor Winpenny and the research team have for the first time demonstrated how qubit rings, pieces of quantum information, can be linked together. The breakthrough, which results from three years research, opens up the possibility of being able to create quantum gates -- a more advanced version of processors found in modern computers. Read more

Supercores Won't Be Easy to Fabricate

by Ron Wilson EE Times, 17 Oct 2005 ARM Ltd. raised few eyebrows with the long-anticipated announcement of its Cortex A8 CPU core a couple of weeks ago. But the launch did raise two important questions: Who really needs a 1-GHz general-purpose CPU core, and if it is needed, who will be capable of implementing it? Read more

Coding for the Optical Channel: The Ghost-Pulse Constraint

by Navin Kashyap, Paul H. Siegel, & Alexander Vardy arXiv.org E-print Archive, 14 Oct 2005 We consider a number of constrained coding techniques that can be used to mitigate a nonlinear effect in the optical fiber channel that causes the formation of spurious pulses, called "ghost pulses." Specifically, if $b_1 b_2 ... b_{n}$ is a sequence of bits sent across an optical channel, such that $b_k=b_l=b_m=1$ for some $k,l,m$ (not necessarily all distinct) but $b_{k+l-m} = 0$, then the ghost-pulse effect causes $b_{k+l-m}$ to change to 1, thereby creating an error. We design and analyze several coding schemes using binary and ternary sequences constrained so as to avoid patterns that give rise to ghost pulses. We also discuss the design of encoders and decoders for these coding schemes. Read more

New Materials and Structures Journal

The Journal of Mechanics of Materials and Structures has as its objective the publication and wide electronic dissemination of innovative and consequential research in mechanics of materials and deformable structures of all types. Analytical, computational, and experimental results must serve to clarify physical phenomena that typically involve small or large deformation states. Methods that can be generalized to a wider class of problems are encouraged. Read more

IEEE-USA Congressional Fellowship

IEEE-USA Congressional Fellowship program was created in 1973 to further the effective use of scientific and technical knowledge in government, to help educate the scientific and engineering community on the public policy process, and to broaden the perspectives of the science, engineering and governmental communities regarding the value of such interaction. Eligible IEEE members are competitively selected to serve a one-year Fellowship, consisting of an appointment to the personal staff of a U.S. Senator or Representative or to the professional staff of a Congressional Committee. Read more

IEEE-USA Engineering and Diplomacy Fellow

IEEE-USA is seeking expressions of interest from IEEE U.S. members interested in spending a year as an IEEE-USA Engineering and Diplomacy Fellow in the U.S. State Department starting in January 2007. The Fellowship provides an opportunity for an engineer to provide technical expertise to the Department, and help raise awareness of the value of engineering input, while learning about and contributing to the foreign policy process. Read more

Shocks in Ion Sputtering Sharpen Steep Surface Features

by H. Henry Chen et al. Science, 14 Oct 2005 We report a regime of ion beam sputtering that occurs for sufficiently steep slopes. High slopes propagate over large distances without dissipating the steepest features. Both the propagation velocity and the dynamically selected slope are universal, independent of the details of the initial shape of the surface. The resulting behavior can be understood as the propagation of a shock front that self-selects a stable slope, as has been previously observed in thin-film fluid flows. Experiments confirm predictions of the theory. An important implication of the propagative behavior at high surface slopes is that a pattern can be fabricated at a large length scale and, through uniform ion irradiation, reduced to a smaller length scale while preserving, or even sharpening, the sharpest features. Read more

Metal-Insulator Transition in Disordered Two-Dimensional Electron Systems

by Alexander Punnoose & Alexander M. Finkel'stein Science, 14 Oct 2005 We present a theory of the metal-insulator transition in a disordered two-dimensional electron gas. A quantum critical point, separating the metallic phase, which is stabilized by electronic interactions, from the insulating phase, where disorder prevails over the electronic interactions, has been identified. The existence of the quantum critical point leads to a divergence in the density of states of the underlying collective modes at the transition, causing the thermodynamic properties to behave critically as the transition is approached. We show that the interplay of electron-electron interactions and disorder can explain the observed transport properties and the anomalous enhancement of the spin susceptibility near the metal-insulator transition. Read more

Free Papers on RF Testing

Thirty free papers on RF testing are available online this month through the IEEE Communications Society's Tech Focus. Tech Focus provides sponsored access to papers from IEEE Communications Society magazines, journals, and conferences on rotating monthly topics. Articles this month include "High-Performance Carrier Interferometry OFDM WLANs", "A Low-Cost Test Solution for Wireless Phone RFICs", and "Structural RFIC Device Testing through Built-In Thermal Monitoring." Read more

Call for Papers - IEEE Communications Magazine

IEEE Communications Magazine has issued a call for papers for upcoming special issues entitled "Scaling the Mobile Internet" and "Open Wireless Architecture and Wireless Convergence." Read more

The Dawn of Digital TV

by Robert M. Rast IEEE Spectrum, October 2005 Analog television prepares to meet its doom, vacating valuable real estate in the radio spectrum -- and the band rush begins. U.S. lawmakers are currently working to free up bandwidth for digital conversion -- a move that could ascribe analog broadcasting to the century's list of extinct technologies. A long line of consumer electronics and communications companies has emerged at the forefront of this congressional maneuver, anxious to bid on the 108 MHz of bandwidth that will lapse in the overthrow of analog broadcasting. Read more

Focus on Blue Sky Electronics

The October issue of Proceedings of the IEEE centers around the revolutionary impact of "blue sky" electronic devices on today's highly evolving technologies. Papers in this issue examine the dimensions of blue sky electronics, which allows for them to process large amounts of information at rapid speeds, and discuss certain blue sky technologies that have met increased dissemination in the marketplace, such as white light bulbs, integrated electronic/biological devices and next-generation technologies like q-dot photonic bandgap lasers and phasmonic devices. Read more

Engineering Education Evolves

by Terry Costlow IEEE-USA Today's Engineer, September 2005 To keep engineering education in the U.S. competitive with other nations such as India and China, many schools are seeking ways to increase retention, generate creative thinking, and acquire a more diverse student body. Colleges and universities are also considering curriculum changes and focusing on ways for students to garner outside charitable and government work experience through engineering projects. Read more

Electricity over Glass

by Anna Basanskaya IEEE Spectrum, October 2005 Running a live wire into a passenger jet's fuel tank seems like a bad idea. Still, sensors that monitor fuel tanks have to run on electricity, soaircraft makers previously had little choice. But what if power could bedelivered over optical fiber instead of copper wire, without fear of shortcircuits and sparks? As it happens, laser and optics company JDS UniphaseCorporation has acquired a small Silicon Valley firm with the technology todo just that. Read more

USAF Funding Opportunity - Control Effectors for Supersonic Tailless Aircraft

This program will develop novel and innovative control effector approaches for supersonic tailless long-range strike aircraft. New concepts that break from current design paradigms could potentially yield lower weight, volume, cost, maintenance, and higher reliability than existing approaches that utilize actuators to deflect the aircraft outer mold line. The contractor shall define, characterize, and substantiate novel innovative control effector concepts that could be combined to provide the control surface power required to maintain Level I flying qualities for a supersonic tailless long-range strike aircraft. Multiple follow-on programs are planned and may be executed, if viable concepts are identified, to perform proof-of-concept demonstration, subsystem definition, system integration and analysis, and subsystem development and demonstration. Read more

Optics Research Garners Nobel in Physics

by Tracy Staedter ScientificAmerican.com, 5 Oct 2005 This year’s Nobel Prize in physics is split between three scientists in the field of optics. Roy Glauber received the award for his theoretical description of the behavior of light particles; John Hall and Theodor Hänsch used that theory to develop a precision laser than can measure the color of the light of atoms and molecules, which can help identify the composition of materials. Read more

Influence of Noncontact Dissipation in the Tapping Mode

by Jean-Pierre Aimé et al. arXive.org E-print Archive, 11 Oct 2005 In the Tapping mode, a variation of the oscillation amplitude and phase as a function of the tip sample distance is the necessary measurement to access quantitatively to the properties of the surface. In the present work, we give a systematic comparison between experimental data recorded on two surfaces, phase and amplitude, and theoretical curves. With an interaction between the tip and the surface taking into account an attractive and a repulsive term, the analytical approach is unable to properly describe the relationship between the phase variation and the oscillation amplitude variation. When an additional dissipation term is involved, due to the attractive interaction between the tip and the surface, the model gives a good agreement with the recorded data. Particularly, the trends in the phase variations related to the noncontact situations have been found to be amenable to an analysis based upon a simple viscoelastic behavior of the surface. Read more

Nonlinear Dynamical Properties of an Oscillating Tip-Cantilever System in the Tapping Mode

by Laurent Nony, Rodolphe Boisgard, & Jean-Pierre Aimé arXiv.org E-print Archive, 11 Oct 2005 The dynamical properties of an oscillating tip-cantilever system are now widely used in the field of scanning force microscopy. The aim of the present work is to get analytical expressions describing the nonlinear dynamical properties of the oscillator in noncontact and intermittent contact situations in the tapping mode. Three situations are investigated: the pure attractive interaction, the pure repulsive interaction, and a mixing of the two. The analytical solutions obtained allow general trends to be extracted: the noncontact and the intermittent contact show a very discriminate variation of the phase. Therefore the measurement of the phase becomes a simple way to identify whether or not the tip touches the surface during the oscillating period. It is also found that the key parameter governing the structure of the dynamical properties is the product of the quality factor by a reduced stiffness. In the attractive regime, the reduced stiffness is the ratio of an attractive effective stiffness and the cantilever one. In the repulsive regime, the reduced stiffness is the ratio between the contact stiffness and the cantilever one. The quality factor plays an important role. For large values of the quality factor; it is predicted that a pure topography can be obtained whatever the value of the contact stiffness. For a smaller quality factor, the oscillator becomes more sensitive to change of the local mechanical properties. As a direct consequence, varying the quality factor, for example with a vacuum chamber, would be a very interesting way to investigate soft materials either to access topographic information or nanomechanical properties. Read more

Chips Give Hope to All-Optical Memory

by Oliver Graydon optics.org News, 12 Oct 2005 The development of all-optical buffers that can delay and temporarily store light pulses has been given a boost with the demonstration of three types of semiconductor device that can perform the task. Scientists at the COM Research Center in Denmark have shown that two popular telecom components -- a quantum-dot semiconductor optical amplifier and an electro-absorption modulator -- can both slow the propagation of light pulses. At the same time, a team from University of California at Berkeley and Texas A&M University has demonstrated that, when configured as an amplifier, a Vertical-Cavity Surface-Emitting Laser can also perform the feat. Read more

Coherent Signal Amplification in Bistable Nanomechanical Oscillators by Stochastic Resonance

by Robert L. Badzey & Pritiraj Mohanty Nature, 13 Oct 2005 Stochastic resonance is a counterintuitive concept: the addition of noise to a noisy system induces coherent amplification of its response. First suggested as a mechanism for the cyclic recurrence of ice ages, stochastic resonance has been seen in a wide variety of macroscopic physical systems: bistable ring lasers, superconducting quantum interference devices, magnetoelastic ribbons and neurophysiological systems such as the receptors in crickets and crayfish. Although fundamentally important as a mechanism of coherent signal amplification, stochastic resonance has yet to be observed in nanoscale systems. Here we report the observation of stochastic resonance in bistable nanomechanical silicon oscillators. Our nanomechanical systems consist of beams that are clamped at each end and driven into transverse oscillation with the use of a radiofrequency source. Modulation of the source induces controllable switching of the beams between two stable, distinct states. We observe that the addition of white noise causes a marked amplification of the signal strength. Stochastic resonance in nanomechanical systems could have a function in the realization of controllable high-speed nanomechanical memory cells, and paves the way for exploring macroscopic quantum coherence and tunnelling. Read more

Synthesis and Properties of Crosslinked Recombinant Pro-Resilin

by Christopher M. Elvin et al. Nature, 13 Oct 2005 Resilin is a member of a family of elastic proteins that includes elastin, as well as gluten, gliadin, abductin and spider silks. Resilin is found in specialized regions of the cuticle of most insects, providing low stiffness, high strain and efficient energy storage; it is best known for its roles in insect flight and the remarkable jumping ability of fleas and spittle bugs. Previously, the Drosophila melanogaster CG15920 gene was tentatively identified as one encoding a resilin-like protein (pro-resilin). Here we report the cloning and expression of the first exon of the Drosophila CG15920 gene as a soluble protein in Escherichia coli. We show that this recombinant protein can be cast into a rubber-like biomaterial by rapid photochemical crosslinking. This observation validates the role of the putative elastic repeat motif in resilin function. The resilience of crosslinked recombinant resilin was found to exceed that of unfilled synthetic polybutadiene, a high resilience rubber. We believe that our work will greatly facilitate structural investigations into the functional properties of resilin and shed light on more general aspects of the structure of elastomeric proteins. In addition, the ability to rapidly cast samples of this biomaterial may enable its use in situ for both industrial and biomedical applications. Read more

Microwave Devices: Carbon Nanotubes as Cold Cathodes

by Kenneth B. K. Teo et al. Nature, 13 Oct 2005 To communicate, spacecraft and satellites rely on microwave devices, which at present are based on relatively inefficient thermionic electron sources that require heating and cannot be switched on instantaneously. Here we describe a microwave diode that uses a cold-cathode electron source consisting of carbon nanotubes1 and that operates at high frequency and at high current densities. Because it weighs little, responds instantaneously and has no need of heating, this miniaturized electron source should prove valuable for microwave devices used in telecommunications. Read more

Surface Alignment of Liquid Crystal Multilayers Evaporated on a Photoaligned Polyimide Film Observed by Surface Profiler

by Thet Naing Oo et al. AZojomo, September 2005 The investigation of the surface alignment of liquid crystal (LC) multilayers evaporated on a photoaligned polyimide vertical alignment (PI-VA) film was carried out by means of a novel three-dimensional (3-D) surface profiler. The photoinduced anisotropy of the partially UV-exposed PI-VA film can be visualized as a topological image of LC multilayers. It seems that the topology of LC multilayers indicates the orientational distribution of LC molecules on the treated film. Moreover, it was shown that the surface profiler can be used to produce non-contact images with high vertical resolution (~ 0.01 nm). Read more

Tribological Properties of Magnesium Matrix Composite Alloys Dispersed with Mg2Si Particles

by Katsuyoshi Kondoh, Ritsuko Tsuzuki, & Eiji Yuasa AZojomo, October 2005 It is important to improve wear resistance and tribological properties of magnesium alloys, in applying them to friction components. However, the conventional magnesium alloys show a low wear resistance due to their low hardness. Therefore, the friction components made of the conventional magnesium alloys are attacked by the counter materials such as steel, copper, and aluminum alloys. In this study, the magnesium matrix composite alloys with Mg₂Si dispersoids were developed via solid-state processing. Mg₂Si has a higher hardness than the conventional steel, for example Mg₂Si bulky materials show micro Vicker’s hardness of 350~700 Hv. Therefore, Mg₂Si particles distributed in the matrix are effective to improve a wear resistance when contacting counter materials. In particular, the composite alloys show a low friction coefficient in an oil lubricant when including Mg₂Si/MgO dispersoids. Read more

Fast Query Processing by Distributing an Index over CPU Caches

by Xiaoqin Ma & Gene Cooperman arXiv.org E-print Archive, 11 Oct 2005 Data intensive applications on clusters often require requests quickly be sent to the node managing the desired data. In many applications, one must look through a sorted tree structure to determine the responsible node for accessing or storing the data. Examples include object tracking in sensor networks, packet routing over the internet, request processing in publish-subscribe middleware, and query processing in database systems. When the tree structure is larger than the CPU cache, the standard implementation potentially incurs many cache misses for each lookup; one cache miss at each successive level of the tree. As the CPU-RAM gap grows, this performance degradation will only become worse in the future. We propose a solution that takes advantage of the growing speed of local area networks for clusters. We split the sorted tree structure among the nodes of the cluster. We assume that the structure will fit inside the aggregation of the CPU caches of the entire cluster. We then send a word over the network in order to examine the tree structure in another node's CPU cache. We show that this is often faster than the standard solution, which locally incurs multiple cache misses while accessing each successive level of the tree. Read more

What Art Is Hiding on Your Microchip?

by Stephen Shankland ZDNet News, 12 Oct 2005 More than 10 years ago, Michael Davidson went looking to capture the beauty of microchip circuitry in photographs. In among the transistors and wire traces, he found something unexpected: Waldo. Read more

Intel Calls the Wi-Fi Shots

by Marguerite Reardon & Dawn Kawamoto ZDNet News, 12 Oct 2005 As they often do when they're not happy with the way things are going, a collection of tech heavy hitters led by Intel may be trying to take control of an important Wi-Fi standards process. Monday's announcement of a group called the Enhanced Wireless Consortium, led by Wi-Fi chipmakers Intel, Broadcom, Marvell and Atheros Communications, is the latest example of a long tradition in tech: The big guys, one way or another, usually end up calling the shots on standards. Read more

Machine Makes Dishes on Demand

by Kim Zetter Wired News, 12 Oct 2005 MIT Media Lab's Counter Intelligence Group, which develops innovative kitchen designs, has created a machine that makes dishes on demand and recycles them after diners have finished a meal. The dishes are made from food-grade, nontoxic acrylic wafers, which are shaped into cups, bowls and plates when heated, then resume their original wafer shape when they are reheated and pressed. Read more

Generating Hope

by Kevin Bullis TechnologyReview.com, 5 Oct 2005 Drinking water infested with germs and parasites or steeped in toxic chemicals is the number-one health problem in the world. It's so big, in fact, that the United Nations has proclaimed 2005-2015 to be the "Water for Life" decade. The UN goal is to get its member nations to honor their commitments to halving the proportion of individuals without access to safe drinking water. Dean Kamen, inventor of the Segway personal transporter, described his design for a simple, energy-efficient water purifier at last week's Emerging Technology Conference. Read more

An Electromechanical Material Testing System for in situ Electron Microscopy and Applications

by Yong Zhu & Horacio D. Espinosa Proceedings of the National Academy of Sciences, 11 Oct 2005 We report the development of a material testing system for in situ electron microscopy (EM) mechanical testing of nanostructures. The testing system consists of an actuator and a load sensor fabricated by means of surface micromachining. This previously undescribed nanoscale material testing system makes possible continuous observation of the specimen deformation and failure with subnanometer resolution, while simultaneously measuring the applied load electronically with nanonewton resolution. This achievement was made possible by the integration of electromechanical and thermomechanical components based on microelectromechanical system technology. The system capabilities are demonstrated by the in situ EM testing of free-standing polysilicon films, metallic nanowires, and carbon nanotubes. In particular, a previously undescribed real-time instrumented in situ transmission EM observation of carbon nanotubes failure under tensile load is presented here. Read more

The "Robust Yet Fragile" Nature of the Internet

by John C. Doyle et al. Proceedings of the National Academy of Sciences, 11 Oct 2005 The search for unifying properties of complex networks is popular, challenging, and important. For modeling approaches that focus on robustness and fragility as unifying concepts, the Internet is an especially attractive case study, mainly because its applications are ubiquitous and pervasive, and widely available expositions exist at every level of detail. Nevertheless, alternative approaches to modeling the Internet often make extremely different assumptions and derive opposite conclusions about fundamental properties of one and the same system. Fortunately, a detailed understanding of Internet technology combined with a unique ability to measure the network means that these differences can be understood thoroughly and resolved unambiguously. This article aims to make recent results of this process accessible beyond Internet specialists to the broader scientific community and to clarify several sources of basic methodological differences that are relevant beyond either the Internet or the two specific approaches focused on here (i.e., scale-free networks and highly optimized tolerance networks). Read more

Vacuum Challenges and Solutions

Physics World, October 2005 Reliability and innovation are touchstones for the vacuum industry in the 21st century. Reliability is needed to get the most out of expensive manufacturing equipment, while innovation is essential to cope with the increasingly complex demands being placed on the suppliers of vacuum equipment by a wide range of customers. This special Physics World supplement starts with a general introduction to vacuum science and technology. This is complemented by a summary of the broad field of vacuum coating, including the crucial process that goes by the name of "sputtering," advice about how a Master's degree can improve your career prospects in the vacuum industry, and a trio of case-studies from different vacuum companies. Read more

Shape Memory Alloy Clamping Devices of a Capsule for Monitoring Tasks in the Gastrointestinal Tract

by A Menciassi et al. Journal of Micromechanics and Microengineering, November 2005 This paper describes the development of an active clamping mechanism to be integrated into a swallowable pill for the diagnosis of the gastrointestinal (GI) tract. The clamping system allows us to stop the pill at desired sites of the GI tract for long monitoring purposes. After discussing the major technical constraints, the design of the core component, i.e. the gripper, based on finite element analysis, is illustrated as well as its fabrication process. Symmetric and asymmetric gripper designs are described. The actuation is provided by shape memory alloys, and it is driven by a dedicated electrical interface. Then the working prototypes have been tested in vitro: for both kinds of grippers a pull-back force up to 0.6 N has been measured. A preliminary theoretical model for the gripper has been derived and compared to the experimental results. Read more

Refraction of Water Waves by Periodic Cylinder Arrays

by Xinhua Hu & C. T. Chan Physical Review Letters, 7 Oct 2005 We show that in the long wavelength limit, water waves propagate through an array of bottom-mounted vertical cylinders as if the water has an effective depth and effective gravitational constant that depends on the filling ratio of the cylinders, leading to refraction phenomena that can be described by analytic formulas. The results are obtained with rigorous homogenization techniques, as well as the multiple scattering formalism that gives full dispersion relationships. This phenomenon provides a mechanism to control the flow of ocean wave energy, as exemplified by a water-wave focusing lens. Read more

Zero Range Model of Traffic Flow

by J. Kaupuzs, R. Mahnke, & R.J. Harris arXiv.org E-print Archive, 8 Oct 2005 A multi-cluster model of traffic flow is studied, in which the motion of cars is described by a stochastic master equation. Assuming that the escape rate from a cluster depends only on the cluster size, the dynamics of the model is directly mapped to the mathematically well-studied zero-range process. Knowledge of the asymptotic behaviour of the transition rates for large clusters allows us to apply an established criterion for phase separation in one-dimensional driven systems. The distribution over cluster sizes in our zero-range model is given by a one-step master equation in one dimension. It provides an approximate mean-field dynamics, which, however, leads to the exact stationary state. Based on this equation, we have calculated the critical density at which phase separation takes place. We have shown that within a certain range of densities above the critical value a metastable homogeneous state exists before coarsening sets in. Within this approach we have estimated the critical cluster size and the mean nucleation time for a condensate in a large system. The metastablity in the zero-range process is reflected in a metastable branch of the fundamental flux-density diagram of traffic flow. Our work thus provides a possible analytical description of traffic jam formation as well as important insight into condensation in the zero-range process. Read more

The Explicit Simplified Interface Method for Compressible Multicomponent Flows

by Bruno Lombard & Rosa Donat arXiv.org E-print Archive, 10 Oct 2005 This paper concerns the numerical approximation of the Euler equations for multicomponent flows. A numerical method is proposed to reduce spurious oscillations that classically occur around material interfaces. It is based on the "Explicit Simplified Interface Method" (ESIM), previously developed in the linear case of acoustics with stationary interfaces. This technique amounts to a higher order extension of the "Ghost Fluid Method" introduced in Euler multicomponent flows. The ESIM is coupled to sophisticated shock-capturing schemes for time-marching, and to level-sets for tracking material interfaces. Jump conditions satisfied by the exact solution and by its spatial derivative are incorporated in numerical schemes, ensuring a subcell resolution of material interfaces inside the meshing. Numerical experiments show the efficiency of the method for rich-structured flows. Read more

Circuit Models for Sierpinski Gasket Antennas

by W. Arrighetti, P. De Cupis, & G. Gerosa arXiv.org E-print Archive, 11 Oct 2005 A lumped-parameter impedor-oriented and a 2-port-network-oriented circuit models for the Sierpinski gasket prefractal antenna are presented. With the former, the voltage and current patterns give a detailed understanding of the electromagnetic fields' self-similar distribution throughout the antenna geometry; on the other hand model complexity exponentially increases with the prefractal iteration order. The latter "black-box" model only controls port-oriented global parameters which are the ones commonly used in antennas' circuit models and its complexity is independent of prefractal order. The "black-box" model is also shown to converge, at fractal limit, to a reciprocal triangular network. Read more

At Dartmouth, A Remote-Controlled Robot

by Kenneth Chang New York Times, 11 Oct 2005 For a steerable piece of dust, look somewhere at Dartmouth College. Researchers there have built what they say is the world's smallest untethered, controllable robot. When placed on a penny, it looks like a mole on the side of Lincoln's chin, measuring a hundredth of an inch by one four-hundredth of an inch. A traffic jam of 200 of them would stretch the length of an M&M. Read more

Hydrogen Power Brewed on the Go

by Helen Knight New Scientist, 1 Oct 2005 A device designed to generate hydrogen for micro fuel cells could help meet the growing power demands of electronic gadgets. Read more

Strap In, Turn On, Blast Off

by Justin Mullins New Scientist, 1 Oct 2005 By day Stuart Ross is an airline pilot. By night he dreams of flying. The sort of flight he has in mind is a million miles from his daily routine: no air traffic control, no passengers and definitely no wings. He dreams of leaping into the air from a standing start, jumping clear over his house, halting motionless hundreds of metres up to admire the view and then descending gracefully back onto his lawn. Ross is tantalisingly close to that goal. He has spent two years and £50,000 building his own shiny jetpack. Along the way, he has scorched his clothes and garden with a fuel so unstable that in a recent accident it turned a section of the UK's busiest motorway into a blazing inferno. And he has almost broken his neck. But at last he's nearly ready to step outside and take to the air. Read more

For Real Strength, Fill It with Holes

by Will Knight New Scientist, 8 Oct 2005 How do you make a structure stronger? The answer, it seems, is to fill it with thousands of holes. It might be seem counterintuitive, but holes can add resilience to a material by absorbing stresses or the energy of an impact. Researchers have come up with a formula for the ideal size and distribution of such cavities. Read more

Vancomycin Covalently Bonded to Titanium Beads Kills Staphylococcus Aureus

by Binoy Jose at al. Chemistry and Biology, September 2005 Periprosthetic infections are life-threatening complications that occur in about 6% of medical device insertions. Stringent sterile techniques have reduced the incidence of infections, but many implant patients are at high risk for infection, especially the elderly, diabetic, and immune compromised. Moreover, because of low vascularity at the site of the new implant, antibiotic prophylaxis is often not effective. To address this problem, we designed a covalent modification to titanium implant surfaces to render them bactericidal. Specifically, we aminopropylated titanium, a widely used implant material and extended a tether by solid phase coupling of ethylene glycol linkers, followed by solid phase coupling of vancomycin. Vancomycin covalently attached to titanium still bound soluble bacterial peptidoglycan, reduced Staphylococcus aureus colony-forming units by 88% ± 16% over 2 hr, and retained antibacterial activity upon a repeated challenge. Read more

Hot New Fuel for Nuclear Reactors

New Scientist, 8 Oct 2005 A fuel pellet that is 50 per cent better at conducting heat will make nuclear power cheaper and more efficient, its developers claim. Engineers from Purdue University in West Lafayette, Indiana, added beryllium oxide to the standard uranium oxide pellets used in light water reactors. Because uranium oxide does not conduct heat well, pellets made of it tend to crack and degrade as the temperature of the reactor core rises and falls, and this means they have to be replaced before all the fuel has been used. Beryllium oxide is a better conductor of heat, so it allows the fuel pellet to cool more efficiently, says Alvin Solomon, who led the research. This means the combined pellet lasts much longer than the standard one. The research is funded by the US Department of Energy.

In-Flight Internet Shown Off by Boeing

by Paul Marks NewScientist.com, 7 Oct 2005 On Friday, at 24,000 feet over the Irish Sea and travelling at 300 knots, a 20-year-old Boeing aeroplane experiences what many experts in radio interference might regard as a “nightmare scenario.” Not only have the passengers been allowed to use cellphones in flight -- not dreadful in itself perhaps -- but the plane is stuffed with the latest technology, all potentially interfering with the plane’s electronics. Read more

Melted by Mistakes

by Edward J. Kramer Nature, 6 Oct 2005 Two-dimensional polymers are potentially useful structures -- if we could only understand their properties. Observations of one polymer’s intricate, two-stage, melting transition may help us do just that. Read more

Relative Risk Analysis of Several Manufactured Nanomaterials

by Christine Ogilvie Robichaud et al. Environmental Science and Technology, 4 Oct 2005 (web release) A relative risk assessment is presented for the industrial fabrication of several nanomaterials. The production processes for five nanomaterials were selected for this analysis, based on their current or near-term potential for large-scale production and commercialization: single-walled carbon nanotubes, bucky balls (C₆₀), one variety of quantum dots, alumoxane nanoparticles, and nano-titanium dioxide. The assessment focused on the activities surrounding the fabrication of nanomaterials, exclusive of any impacts or risks with the nanomaterials themselves. A representative synthesis method was selected for each nanomaterial based on its potential for scaleup. A list of input materials, output materials, and waste streams for each step of fabrication was developed and entered into a database that included key process characteristics such as temperature and pressure. The physical-chemical properties and quantities of the inventoried materials were used to assess relative risk based on factors such as volatility, carcinogenicity, flammability, toxicity, and persistence. These factors were first used to qualitatively rank risk, then combined using an actuarial protocol developed by the insurance industry for the purpose of calculating insurance premiums for chemical manufacturers. This protocol ranks three categories of risk relative to a 100 point scale (where 100 represents maximum risk): incident risk, normal operations risk, and latent contamination risk. Results from this analysis determined that relative environmental risk from manufacturing each of these five materials was comparatively low in relation to other common industrial manufacturing processes. Read more

Photonic Innovations Move into the Mainstream

by Tami Freeman fibers.org News, 4 Oct 2005 Innovation has always been key for optical-component makers, and never more so than in the current cost-sensitive telecoms market. Three technologies -- liquid crystals, polymer components, and long-wavelength VCSELs -- are rapidly gaining widespread commercial acceptance. Read more

Solar Breakthrough Will Help Spur Viability of Alternative Energy

New Mexico State University Press Release, 7 Oct 2005 Imagine being able to paint your roof with enough alternative energy to heat and cool your home. What if soldiers in the field could carry an energy source in a roll of plastic wrap in their backpacks? Those ideas sound like science fiction þu particularly in the wake of the rising costs of fossil fuel. But both are on the way to becoming reality because of a breakthrough in solar research by a team of scientists from New Mexico State University and Wake Forest University. Read more

UCLA Engineers Pioneer Affordable Alternative Energy Solar Cells

University of California - Los Angeles Press Release, 9 Oct 2005 With oil and gas prices in the United States hovering at an all-time high, interest in renewable energy alternatives is again heating up. Researchers at the UCLA Henry Samueli School of Engineering and Applied Science hope to meet the growing demand with a new and more affordable way to harness the sun's rays: using solar cell panels made out of everyday plastics. Read more

New Study Weighs Impact of Open Access on Scholarly Journals

American Association for the Advancement of Science Press Release, 11 Oct 2005 There has been a proliferation of open access journals during the past decade and considerable debate about their potential impact on traditional scientific journals such as Science, published by AAAS, and Nature. The first substantial study of the quickly evolving landscape of open-access publishing has found that about 40 per cent of the surveyed journals providing full open access to their articles are not yet covering their costs and face an uncertain financial future. Read more

Heat and Electricity Generator That Reduces Contaminant Emissions

Basque Research Press Release, 11 Oct 2005 The process of generating heat and electricity with this type of cell is more direct and, thus, efficiency is increased. Traditional methods have to burn a fossil fuel in order to produce heat which, in turn, is transformed into mechanical work by means of a thermal engine. This engine is what drives the electric generator that produces electricity. Fuel cells, on the other hand, produce electricity directly by means of an electrochemical process, using fuels such as natural gas or butane, without the need for combustion. Read more

Wi-Fi and Cellular Accelerate Convergence

by Patrick Mannion EE Times, 10 Oct 2005 Six years after the emergence of the IEEE 802.11b/a standard, wireless and wired carriers and operators alike are moving en masse toward converged services over cellular and Wi-Fi networks. Read more

On the Road to Networked Vehicles

by Christoph Hammerschmidt EETimes Germany, 10 Oct 2005 Traditional issues such as reliability and architectural complexity took a back seat at this year's Congress on Electronic Systems for Vehicles as developers instead focused on innovation in areas like electronic braking and steering systems and emerging hybrid drives. Read more

On the Capacity of Mobile ad hoc Networks with Delay Constraints

by Cristina Comaniciu & H. Vincent Poor arXiv.org E-print Archive, 10 Oct 2005 Previous work on ad hoc network capacity has focused primarily on source-destination throughput requirements for different models and transmission scenarios, with an emphasis on delay tolerant applications. In such problems, network capacity enhancement is achieved as a tradeoff with transmission delay. In this paper, the capacity of ad hoc networks supporting delay sensitive traffic is studied. First, a general framework is proposed for characterizing the interactions between the physical and the network layer in an ad hoc network. Then, CDMA ad hoc networks, in which advanced signal processing techniques such as multiuser detection are relied upon to enhance the user capacity, are analyzed. The network capacity is characterized using a combination of geometric arguments and large scale analysis, for several network scenarios employing matched filters, decorrelators and minimum-mean-square-error receivers. Insight into the network performance for finite systems is also provided by means of simulations. Both analysis and simulations show a significant network capacity gain for ad hoc networks employing multiuser detectors, compared with those using matched filter receivers, as well as very good performance even under tight delay and transmission power requirements. Read more

Driverless VW Wins $2 Million Robot Race

CNN.com, 10 Oct 2005 An unmanned vehicle has successfully navigated a forbidding 132-mile section of the Mojave Desert. The next stop for the technology may be Afghanistan or Iraq. A souped-up VW Touareg, designed by Stanford University, zipped through the course in six hours and 53 minutes Sunday, using only its computer brain and sensors to navigate rough and twisting desert and mountain trails. Read more

Engineers Probe New Orleans Levees

CNN.com, 10 Oct 2005 Hoping to prevent past mistakes during the rebuilding process, civil engineers gathered in New Orleans to determine how Hurricane Katrina breached the city's levees, flooding 80 percent of the city. The central issue they grappled with: Did Katrina overwhelm the city's flood defenses with a torrent they weren't designed to contain? Or did faulty construction or maintenance cause them to burst open at water levels well within their capacity? Read more

Fuel Cells 'Need Political Push'

by Jo Twist BBC News, 5 Oct 2005 The world must actively push for cleaner energy technologies such as fuel cells, says Sir David King, the UK government's chief scientific advisor. But there needs to be a cultural shift in energy production, he told delegates at a fuel cell symposium in London. Read more

Europe Needs Bigger Robots Push

BBC News, 7 Oct 2005 European Union member states are losing out to the Japanese when it comes to developing useful robots that are commercially available. The European Commission urged businesses to turn their robotics research into viable products much more quickly than they do now. Read more

Japan Tests Supersonic Jet Model

BBC News, 10 Oct 2005 Japan's Aerospace Exploration Agency has successfully tested a new design for a supersonic airliner. An 11m (36ft) scale model was launched by rocket from the test site at Woomera in the Australian desert. Officials at the aerospace agency said the test marked a major step forward in the development of supersonic flight technology. Read more

Wireless Industry Comes Together for Faster Wi-Fi

USATODAY.com, 10 Oct 2005 A group of 27 technology companies said on Monday they would collaborate on a new, faster Wi-Fi wireless Internet connection standard for computers and other portable devices. The alliance, dubbed Enhanced Wireless Consortium, joins previously separated camps that were heading towards separate standards for wireless networking. Read more

The Silicon Solution

by Mario Paniccia & Sean Koehl IEEE Spectrum, October 2005 The relentless push of Moore’s Law has allowed data rates to soar, Internet traffic to swell, and wired and wireless technology to cover continents. Increasingly, we all expect fast, free-flowing bandwidth whenever and wherever we connect with the world. Within the next decade, the circuitry embodied by a rack of today’s servers, able to churn through billions of bits of data per second and handle all the data-processing needs of a small company, will fit neatly on a single silicon chip half the size of a postage stamp. Read more

Rise of the Body Bots

by Erico Guizzo & Harry Goldstein IEEE Spectrum, October 2005 Science fiction fans have long become accustomed to the idea of steely commandos clad in robotic exoskeletons taking on huge, vicious, extraterrestrial beasts, shadowy evil cyborgs, or even each other. Supersoldiers encased in sleek, self-powered armor figure memorably in such works as Robert A. Heinlein’s 1959 novel Starship Troopers, Joe W. Haldeman’s 1975 The Forever War, and many other books and movies. In 1999’s A Good Old-Fashioned Future, for example, Bruce Sterling writes of a soldier dying after crashing in his “power-armor, a leaping, brick-busting, lightning-spewing exoskeleton.” Today, in Japan and the United States, engineers are finally putting some practical exoskeletons through their paces outside of laboratories. Read more

Light from Silicon

by Salvatore Coffa IEEE Spectrum, October 2005 Silicon’s absence from critical optical applications has long bothered semiconductor specialists. If photons could be easily coaxed from silicon, we could do marvelous things. Imagine plugging your office PC into an optical-fiber local area network and pulling files from a distant server at tens of gigabits per second -- enormous, highdefinition video files popping onto the screen instantaneously. Optical fibers linking the microchips within a PC would accelerate its computing speed as bandwidth bottlenecks from its motherboard’s copper wiring disappeared. The key to that vision is the fabrication of efficient, electrically driven light sources that work at room temperature and are produced using materials and processes compatible with the manufacturing methods currently used to make ordinary silicon memory and microprocessor chips. Read more

Fiber to the Brain

by Willie D. Jones IEEE Spectrum, October 2005 Today, surgical procedures for implanting electronic devices that stimulate the heart muscle to correct abnormal cardiac rhythms are considered routine. But addressing the brain in this way -- and reaching areas deep within the cerebral mass without destroying neurons en route -- is another matter. While surgeons have successfully installed electrodes in the brain that have restored a semblance of sight or hearing, stopped the tremors of Parkinson’s disease, and cataloged the brain’s responses to environmental stimuli, they’ve always had to break in through the skull. That procedure damages healthy brain tissue, exposes patients to infection, and leaves wires sticking out of their heads. And over time, scar tissue forms around the electrodes, encapsulating them and isolating them from the active brain tissue. Now a promising new procedure has been proposed. Read more

Farther and Faster at the Speed of Light

by Scott Kipp oemagazine, October 2005 As disk-drive interfaces increased in speed during the 1990s, the distance limitations of the parallel small-computer-systems interface (SCSI) bus became apparent. Each time the speed of the SCSI bus increased, the supported distance decreased because of the limitations of the copper cabling. To overcome these distance limitations and offer a networked architecture, the American National Standards Institute decided to define Fibre Channel and, thus, storage-area networks. The Fibre Channel name implies the use of optic fiber to interconnect storage devices and servers via channels (high-bandwidth connections). Read more

Nanoscale Imaging of Buried Structures via Scanning Near-Field Ultrasound Holography

by Gajendra S. Shekhawat & Vinayak P. Dravid Science, 7 Oct 2005 A nondestructive imaging method, scanning near-field ultrasound holography (SNFUH), has been developed that provides depth information as well as spatial resolution at the 10- to 100-nanometer scale. In SNFUH, the phase and amplitude of the scattered specimen ultrasound wave, reflected in perturbation to the surface acoustic standing wave, are mapped with a scanning probe microscopy platform to provide nanoscale-resolution images of the internal substructure of diverse materials. We have used SNFUH to image buried nanostructures, to perform subsurface metrology in microelectronic structures, and to image malaria parasites in red blood cells. Read more

PbSe Nanocrystal Solids for n- and p-Channel Thin Film Field-Effect Transistors

by Dmitri V. Talapin & Christopher B. Murray Science, 7 Oct 2005 Initially poorly conducting PbSe nanocrystal solids (quantum dot arrays or superlattices) can be chemically "activated" to fabricate n- and p-channel field effect transistors with electron and hole mobilities of 0.9 and 0.2 square centimeters per volt-second, respectively; with current modulations of about 10³ to 10⁴; and with current density approaching 3 x 10⁴ amperes per square centimeter. Chemical treatments engineer the interparticle spacing, electronic coupling, and doping while passivating electronic traps. These nanocrystal field-effect transistors allow reversible switching between n- and p-transport, providing options for complementary metal oxide semiconductor circuits and enabling a range of low-cost, large-area electronic, optoelectronic, thermoelectric, and sensing applications.

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IEEE Press Seeks Book Proposals

by Erica Vonderheid The Institute Online, 5 Oct 2005 Want to be an author? Think you have a book in you? IEEE Press is looking for proposals for how-to books that help technologists perform their jobs. The Press will focus most of its acquisition efforts on its five most commercially successful technical topics: power engineering, electromagnetic wave theory, microelectronics, biomedical engineering, and communications. Proposals are also needed for books on emerging technical areas such as computational intelligence, which deals with adaptive mechanisms that facilitate the intelligent behavior of machines. Read more

DARPA Solicitation - Wireless Network after Next

The Wireless Network after Next (WNaN) program seeks to develop and demonstrate technologies and system concepts that will enable intelligent adaptive wireless networks consisting of densely deployed low cost wireless nodes. The premise of the WNaN program is that significant advantages can be realized by densely deploying low cost nodes which have been jointly optimized with network operations. WNaN networks should adapt to changing conditions by adjusting the topology of the network and the operational mode of the nodes to reduce the demands on the nodes in particular on the physical and link layers. By working around the limitations of the low-cost nodes that form the network, and by utilizing the rich interconnection fabric created by dense deployment, the WNaN network should provide reliable and highly available battlefield communications at a low system cost. Read more

DARPA Takes Another Look at Improving Machine Learning

by John Keller Military & Aerospace Electronics, September 2005 Scientists at the U.S. Defense Advanced Research Projects Agency are approaching industry about a research project to advance the state of the art in computer learning. Read more

The Evolution of UAV Avionics

by J.R. Wilson Military & Aerospace Electronics, September 2005 The military, once again, is the technology leader when it comes to the aviation electronics of unmanned aerial vehicles (UAV), which is growing in sophistication with each passing year and leading many experts to consider applying UAV avionics technologies even to manned aircraft. Read more

Mobility Standard

by Steve Given Military Information Technology, October 2005 The use of mobilized computing in the military has grown at an astounding rate over the last few years. As new technology becomes available, higher performing portable systems provide the soldier with tools that help complete critical missions. One of the new technologies that has helped advance the development of the communication battlefield is the embedded computer module. Read more

Engine Ratings Get a New Equalizer

by Kevin Cameron New York Times, 3 Oct 2005 Proud new owners were once greeted with a universal request for some measure of their car's performance. A recent change in the procedures for measuring horsepower is leveling the field, and causing the horsepower figures of some vehicles to be revised. Read more

All-Optical Silicon Switch Takes Control of the Light

by Tami Freeman fibers.org News, 3 Oct 2005 All-optical switching of light on a silicon platform is a key objective for researchers looking to create highly integrated optical devices. But silicon’s lack of nonlinear optical properties makes this a challenging task, and one that to date has only been realized in large structures with high power requirements. Read more

DIMM Buffs Up to Jog Memory

by Kevin Kilbuck EE Times, 3 Oct 2005 As the data rate of DDR memory moves into the DDR2 range, the need increases in such applications as servers, workstations and high-performance communications equipment for a new memory system topology to deliver the optimum combination of data throughput and system capacity. Read more

Chip-Enabled Ball Makes Goal-Line Decisions

by Peter Clarke EE Times, 3 Oct 2005 An RF integrated circuit developed in Germany is being tested in Peru as a means to determine goal-line decisions in soccer matches. The chip-enabled football has been developed by sports giant Adidas, software company Cairos Technologies AG, and engineers from Germany’s Fraunhofer Institute. Read more

Heavy Metal Makes Lighter Planes

by Patrick Gray Wired News, 27 Sep 2005 The distinctive growl of a light plane may soon be accompanied by an eerie hum, thanks to Australian research that shows the effectiveness of aircraft wings is dramatically increased when sound is applied to them. Qantas engineer Ian Salmon tested wing sections covered with a piezoelectric material that vibrates when a current is applied to it. When the tone of the sound was at its most effective pitch, Salmon's wing panel achieved 22 percent more lift than it would have without the piezoelectric hum. Read more

'Doom' Rocket Man Preps for Liftoff

by Michael Belfiore Wired News, 30 Sep 2005 The burgeoning commercial spaceflight industry is about to hold its first big convention, replete with rocket launches, flying space vehicles and the first demonstration of games whiz John Carmack's spaceship-in-progress. The X Prize Cup will touch down Oct. 6 in Las Cruces, New Mexico, not far from the Roswell of UFO lore and the White Sands Missile Range. Read more

Purdue Nanotechnology Center Focuses on Discovery

by Rick Callahan USATODAY.com, 2 Oct 2005 In their shiny new laboratories at Purdue University's Birck Nanotechnology Center, scientists are working on a mindbogglingly tiny scale -- a realm in which a grain of sand would loom as a mountainous cube. Read more

Counties Switch to Biodiesel School Buses

by Brian Farkas USATODAY.com, 2 Oct 2005 Sherry Dean has a secret she's been keeping from her drivers since March -- their Upshur County school buses are running on an alternative fuel made of vegetable oil and diesel. So far, the results have been "great." Read more