Wave propagation phenomena in soils can be experimentally simulated using centrifuge scale models.  An original excitation device (drop-ball arrangement) is proposed to generate short wave trains.  Wave reflections on model boundaries are taken into account and removed by homomorphic filtering.  Propagation is investigated through dispersion laws.  For drop-ball experiments, spherical wave field analysis assuming linear [...]

The direct analysis of the dynamic response of materials is possible using Split Hopkinson pressure bar method.  For soils, it has to be adapted since the specimen has generally poor mechanical properties.  An original experimental arrangement called “Three-Dimensional Split Hopkinson Pressure Bar” is proposed.  It allows the measurement of the complete three-dimensional dynamic response of [...]

First we present and theoretically analyze the phenomenological physical picture behind Vibration-Induced Conductivity Fluctuations.  We identify the relevant tensors characterizing the electromechanical response against the vibrations for both longitudinal and transversal responses.  We analyze the conductivity response with acceleration type vibrations and a new scheme, measurements with more advantageous compression type vibrations that are first [...]

Around 20% of accidents on multi-lane highways are the result of driver fatigue.  So the Japanese car maker Toyota has developed a system to rouse drivers before they quite literally drift off completely.  [NewScientist.com, 23 Jan 2009]

Harvard architecture CPU design is common in the embedded world.  Examples of Harvard-based architecture devices are the Mica family of wireless sensors.  Mica motes have limited memory and can process only very small packets.  Stack-based buffer overflow techniques that inject code into the stack and then execute it are therefore not applicable.  It has been [...]

A Purdue University study has found that the best way to get students interested in engineering and technology at an early age may be to focus less on textbooks and more on interactive, problem-solving design projects.  Melissa Dark, assistant dean for strategic planning in the College of Technology, was one of the leaders of the [...]

U.S. scientists say they are attempting to build neurons from carbon nanotubes to emulate human brain function.  “At this point we still don’t know if building a synthetic brain is feasible,” said University of Southern California Professor Alice Parker.  “It may take decades to realize anything close to the human brain, but emulating pieces of [...]

More than a quarter of the nation’s bridges are structurally deficient or functionally obsolete.  Leaky pipes lose an estimated seven billion gallons of clean drinking water every day.  And aging sewage systems send billions of gallons of untreated wastewater cascading into the nation’s waterways each year.  These are among the findings of a report to [...]

The race is on to find the ideal battery chemistry for plug-in hybrids and all-electric vehicles, but a startup in Indiana believes that a combination of different storage technologies might be the best way to improve vehicle performance and reduce cost.  The company’s technology allows vehicles to run on a combination of fuel cells, ultracapacitors, [...]

Monitoring the structural safety of the nation’s bridges may get a boost from wireless and green technologies.  Engineers at University of Texas at Austin are trying to design small wireless sensors to monitor bridges.  The work will be a collaboration between several different departments at UT, including civil, electrical, and mechanical engineering.  The United States [...]